Browse Topic: Hardening

Items (900)

Heat Treatment, Precipitation-Hardening Corrosion-Resistant, Maraging, and Secondary Hardening Steel Parts

7/21/2026

This specification, in conjunction with the general requirements for steel heat treatment covered in AMS2759, establishes the requirements for heat treatment of precipitation-hardening corrosion-resistant, maraging, and secondary hardening steel parts. Parts are defined in AMS2759. Parts made from steels other than those specified in this specification may be heat treated in accordance with the applicable requirements herein using processing temperatures, times, and other parameters recommended by the material producer unless otherwise specified by the cognizant engineering organization. General ordering instructions are specified in AMS2759.

AMS F Corrosion and Heat Resistant Alloys Committee

Genetic Algorithm Based Optimization of Chaboche Kinematic Hardening Parameters along with the Validation of FE Model through Characterized Crack Initiation

2026-28-0086

2/12/2026

In the context of electro-mobility for commercial vehicles, the failure analysis of a connector panel in a DCDC converter is crucial, particularly regarding crack initiation at the interface of busbar and plastic component. This analysis requires a thorough understanding of thermo-mechanical behavior under thermal cyclic loads, necessitating kinematic hardening material modeling to account for the Bauschinger effect. As low cycle fatigue (LCF) test data is not available for glass fiber reinforced polyamide based thermoplastic composite (PA66GF), we have adopted a novel approach of determining non-linear Chaboche Non-Linear Kinematic Hardening (NLK) model parameters from monotonic uniaxial temperature dependent tensile test data of PA66GF. In this proposed work a detailed discussion has been presented on manual calibration and Genetic Algorithm (GA) based optimization of Chaboche parameters. Due to lack of fiber orientation dependent test data for PA66GF, here von Mises yield criteria based Chaboche NLK model is implemented as a macro-mechanical phenomenological model based on test data with random fiber orientation. After material modelling as described above the thermo-mechanical finite element (FE) simulation has been conducted on Connector panel assembly with temperature cycling from -40°C to 80°C. The assembly under consideration is composed of busbars, insert mold and outer connector body of plastic PA66GF. It is observed from the simulation result that though the equivalent plastic strain is much higher at 80°C in comparison to the same at -40°C, the equivalent von Mises stress is comparatively lower at 80°C than at -40°C because of Bauschinger effect while reversing load, which in turn validates the implementation of proper kinematic hardening material model to address the physical phenomenon. Finally, the FE model is validated through characterized crack initiation site in the plastic component comparing with equivalent plastic strain, von Mises stress and stress triaxiality evaluated from simulated result.

Basu, Parichay, Srinivasappa, Naveen

Incorporation of Strain Hardening and Sheet Thinning Effects during Forming Process for an Accurate Prediction of Buckling Loads on Sheet Metal Axle Parts

2026-26-0391

1/16/2026

In the automotive industry, during the early phase of development, numerical prediction of strength and durability of chassis parts become crucial as these predictions help in design optimization, selecting the appropriate material and identifying potential issues before physical prototypes are built. One of the crucial simulation requirements is the prediction of accurate load carrying capacity or bucking load of axle links. When it comes to the sheet metal axle links there is a deviation in the hardware test and CAE results for load carrying capacity due to the non-integration of forming effects in the numerical simulation, resulting in overdesign of parts, increased costs and development time. This study aims to address these challenges by integrating forming effects experienced by the part during forming process into static strength simulations. These effects include plastic straining, which contributes to material strain hardening and local thickness changes that lead to thinning. Both parameters are critical for accurately predicting the load carrying capacity of sheet metal axle parts. A multi-step forming simulation is carried out on a rear-axle sheet metal link, which involves simulating all the stages of the forming process to accurately predict the plastic strains and thickness changes. The forming simulations are performed using the anisotropic material model Banabic-Barlat-Comsa (BBC) to capture the anisotropy effects. This model uses several coefficients to precisely characterize the yield surfaces, considering both uniaxial and biaxial yield stresses, as well as anisotropy coefficients. The output of the forming simulation, Equivalent Plastic Strain (EPS) and thickness data, are then mapped on to the FEA model as initial conditions for static strength calculation.

R B, Govind, Selvaraj, Nirmal Velgin

Evaluation of Shear Trim Edge in HSLA Steel for Automotive Application

2026-26-0286

1/16/2026

Quality of the Shear Trimmed edge of HSLA 550 steels is significantly affected by process variations such as Shear Trimming Clearance, trim tolerance, burr height and clamping force. All these parameters largely influence the characteristics of the Shear Affected Zone, a region on sheet metal where it undergoes deformation during the trimming process. The Shear Affected Zone is predominantly vulnerable to failure due to work hardening and the effects of strain rate, induced by the tonnage during the trimming operation. To assess the edge ductility of these materials, Tensile, Fatigue Strength, Die Punch Clearance, Roughness and Hardness Tests are carried out. These tests are crucial for applications that demand high formability and resistance to edge failure. Virtual simulation of edge trimming operation using elastoplastic material models in LS-Dyna have been performed to gain insights into burr formation and damage evolution during shearing. These simulations act as a precursor to determine the sets of tests to be carried out and eliminate the factors with minimal effects in the edge behavior coupon tests. These insights are decisive to enhance the performance of HSLA 550 grade steel used in automotive applications. By understanding the relationship between these properties and trim edge ductility, Engineers can make informed decisions to improve the durability and reliability of components made from this material during concept development.

Thota, Badri Vishal, Kashyap, Amit, Bhuvangiri, Jaydev

Non-Metallic Inclusions in Carburizing Steels as a Contributory Factor for the Formation of Carbide Net

2026-26-0290

1/16/2026

The article deals with the issue of identifying structural defects that contribute to the formation of a carbide net during thermochemical treatment of steel parts, which negatively affects the mechanical properties complex of finished products. Based on the available data, a theory has been put forward regarding the influence of the present non-metallic inclusions in the carburizing steels structure on carbide formation process in the hardened layer. As an experimentally the samples have been produced from the varying chemical composition alloy structure carburized steel (0.17-0.23 % C, 0.17-0.37 % Si, 0.80-1.10 % Mn, 1.00-1.30 % Cr, 0.03-0.09 % Ti). During microstructure analysis of the samples it has been establish that non-metallic inclusions, in particular sulfides, contribute to the formation of carbides and carbide net in steel due to their high chemical activity with carbon. Thus, contamination of the metal of carburizing steels with non-metallic inclusions is not only a defect in itself, but also causes the occurrence of other structural defects during subsequent thermochemical and thermal treatment.

Runova, Iuliia, Chatkina, Mariia, Musienko, Aleksandr

Optimization of Global and Local Formability Properties through Nb Microalloying

2026-26-0303

1/16/2026

David Martin, CBMM Asia Bernardo Barile, CBMM Europe BV Caio Pisano, CBMM Europe BV Automotive high strength steels have specific microstructure-dependent forming characteristics. Global formability is generally associated with high uniform strain values which imply good drawability and stretch forming properties driven by pronounced work hardening. Local formability on the other hand is often measured by various fracture strain values—generally higher in single phase steels. In this respect, the so-called ‘local/global formability map’ concept has been established not only to provide a comprehensive methodology to characterize existing automotive steels but also to enable improvement strategies toward more balanced forming characteristics. Niobium (Nb) microalloying is a powerful tool to achieve both property improvement in general and property balance in particular. More than two decades of research has demonstrated that Nb-induced microstructural optimization is applicable to HSLA steels, AHSS (DP, CP, TRIP, TWIP) and PHS, and it has been realized in commercial production of such steels. This contribution details the underlying metallurgical and processing effects of Nb microalloying in automotive high-strength steels and highlights achieved global and local formability improvements. Respective optimization vectors are demonstrated through intrinsic formability mapping, where the possibilities and limitations are indicated.

Barile, Bernardo

Evaluating the Influence of Material Properties and Hardness on Tightening Torque

2025-28-0255

11/6/2025

Earthmoving machines are equipped with a variety of ground-engaging tools that are joined by bolted connections to improve serviceability. These tools are made from heat-treated materials to enhance their wear resistance. Attachments on earthmoving machines, including buckets, blades, rippers, augers, and grapples, are specifically designed for tasks such as digging, grading, lifting, and breaking. These attachments feature ground-engaging tools (GET), such as cutting bits or teeth, to protect the shovel and other earthmoving implements from wear. Torquing hardened plates of bolted joint components is essential to ensure uniform load distribution and prevent premature failure. Therefore, selecting the proper torque is an important parameter. This study focuses on analyzing various parameters that impact the final torque on the hardened surface, which will help to understand the torque required for specific joints. Several other parameters considered in this study include hardware material, coefficient of friction, end bit and cutting-edge material, and their hardness. Understanding the influence of surface hardness on bolted joint torque is crucial for optimizing performance, reliability, and longevity of bolted connections in various engineering applications

Parameswaran, Sankaran Potti, Bhosale, Dhanaji, Kumar, Rajeev

A New Methodology to Characterize the Influence of Paint Baking and Pre-Straining on the Tensile Properties of Third Generation Advanced High Strength Steels

2025-01-8223

4/1/2025

The current ASTM A653 standard for determining the bake hardening index (BHI) of sheet metals can lead to premature fracture at the transition radius of the tensile specimen in high strength steel grades. In this study, a new test procedure to characterize the BHI was developed and applied to 980 and 1180 MPa third generation advanced high strength steels (3G-AHSS). The so-called KS-1B methodology involves pre-straining over-sized tensile specimens followed by the extraction of an ASTM E8 sample, paint baking and re-testing to determine the BHI. Various pre-strain levels in the range of 2 to 10% were considered to evaluate the KS-1B procedure with select comparisons with the ASTM A653 methodology for pre-strain levels of 2 and 8%. Finally, to characterize the influence of paint baking at large strain levels, sheared edge conical hole expansion tests were conducted. The tensile mechanical properties of the 3G steels after paint baking were observed to be sensitive to the pre-strain with bake hardening indices exceeding 100 MPa. However, the sheared edge formability was not significantly affected by paint baking.

Northcote, Rhys, Berry, Avalon, Narayanan, Advaith, Tolton, Cameron, Lee, Haea, Smith, Jonathan, McCarty, Eric, Butcher, Cliff

Microstructure, Tensile and Fracture Behaviors of Squeeze Cast Wrought Mg Alloy AZ80

2025-01-8230

4/1/2025

Wrought magnesium alloy AZ80 with a thick section of 20 mm was prepared by squeeze casting (SC) and permanent steel mold casting (PSMC). The porosity measurements of the SC and PSMC showed that the SC AZ80 had a porosity of 0.52%, which was the 77% lower than that (2.21%) of the PSMC counterpart. The microstructure analyses and phase identification indicated that the cast AZ80 alloy consisted of a primary α-Mg phase, eutectic Mg-Al-Zn phases and Al-Mn intermetallic. The fine primary α-Mg dendrites and a high amount of the intermetallic phase were present in the SC AZ80 alloy. The yield strength (YS), ultimate yield strength (UTS), elongation (ef), elastic modulus (E) and strain hardening rate of the cast AZ80 specimens were evaluated by tensile testing. The measured engineering stress versus strain curves showed that the SC AZ80 alloy exhibited 84.68 MPa in YS, 168.23 MPa in UTS, 5.07% in ef, and 25.1GPa in modulus while the YS, UTS and ef of the PSMC specimen were only 71.61 MPa, 109.04 MPa, 1.85% and 21.9GPa. The calculated resilience and tensile toughness indicated that the SC AZ80 was more capable of resisting energy loads in elastic deformation and had an ability to absorb energy during plastic deformation than that of the PSMC AZ80. Also, the analyses of the true stress versus strain curves revealed that, upon the onset of plastic deformation, the strain-hardening rate of the SC AZ80 sample was 10,341 MPa, which was 9% higher than that (9,489 MPa) of the PSMC AZ80 specimen. The obtained mechanical properties showcased the fit of the casting process to wrought magnesium AZ80 alloy, which was squeeze casting. The low porosity level, fine dendritic structure and a high content of intermetallic phase should be somewhat responsible for high mechanical properties of the SC AZ80 alloy.

Ying, Peilin, Hu, Henry, Hu, Anita, Shen, Wutian

Steel, Corrosion-Resistant, Bars, Wire, Forgings, Mechanical Tubing, and Rings 16Cr - 4.0Ni - 0.30Cb - 4.0Cu Consumable Electrode Remelted Solution Heat Treated, Precipitation Hardened (H900)

AMS5622/H900 (Historical)

2/25/2025

This specification covers a corrosion-resistant steel product 8 inches (203 mm) and under in nominal diameter, thickness, or for hexagons least distance between parallel sides in the solution and precipitation heat-treated (H900) condition.

AMS F Corrosion and Heat Resistant Alloys Committee

Steel, Corrosion-Resistant, Bars, Wire, Forgings, Mechanical Tubing, and Rings 16Cr - 4.0Ni - 0.30Cb - 4.0Cu Consumable Electrode Remelted Solution Heat Treated, Precipitation Hardened (H925)

AMS5622/H925 (Historical)

2/25/2025

AMS F Corrosion and Heat Resistant Alloys Committee

Steel, Corrosion-Resistant, Bars, Wire, Forgings, Mechanical Tubing, and Rings 16Cr - 4.0Ni - 0.30Cb - 4.0Cu Consumable Electrode Remelted Solution Heat Treated, Precipitation Hardened (H1150)

AMS5622/H1150 (Current)

2/25/2025

AMS F Corrosion and Heat Resistant Alloys Committee

Steel, Corrosion-Resistant, Bars, Wire, Forgings, Mechanical Tubing, and Rings 16Cr - 4.0Ni - 0.30Cb - 4.0Cu Solution Heat Treated, Precipitation Hardened (H1025) Consumable Electrode Remelted

AMS5622/H1025A (Current)

2/25/2025

AMS F Corrosion and Heat Resistant Alloys Committee

Steel, Corrosion-Resistant, Bars, Wire, Forgings, Mechanical Tubing, and Rings 16Cr - 4.0Ni - 0.30Cb - 4.0Cu Consumable Electrode Remelted Solution Heat Treated, Precipitation Hardened (H1075)

AMS5622/H1075 (Current)

2/25/2025

AMS F Corrosion and Heat Resistant Alloys Committee

Steel, Corrosion-Resistant, Bars, Wire, Forgings, Mechanical Tubing, and Rings, 16Cr - 4.0Ni - 0.30Cb - 4.0Cu, Consumable Electrode Remelted, Solution Heat Treated, Precipitation Hardened (H1100)

AMS5622/H1100 (Current)

2/25/2025

AMS F Corrosion and Heat Resistant Alloys Committee

Effect of Hardening and Tempering Temperatures on the Mechanical Behavior of Alloy Steel

2025-28-0027

2/7/2025

Alloy steel possesses high strength, hardenability, fatigue strength, and good impact toughness. It is widely used for making various machine parts, automobile components, shafts, gears, connecting rods, and more. Hardening and tempering develop the optimum combination of hardness, strength, and toughness in engineering steel, thereby providing components with high mechanical properties. Hardening and tempering temperatures are crucial factors that affect the mechanical and metallurgical properties of 42Cr4Mo steel. In this research work, 42Cr4Mo alloy steel samples were subjected to hardening and tempering processes. The hardening temperatures were set at 830°C, 850°C, and 870°C, while the tempering temperatures were maintained at 590°C and 650°C. The test results show that hardening at 830°C and tempering at 590°C achieve high tensile strength, which decreases as the temperature increases. Different hardening temperatures and constant tempering temperatures will be optimized to achieve the desired hardness, ultimate tensile strength, yield strength, impact resistance, and metallurgical properties. These parameters significantly contribute to determining the appropriate.

Murugesan, Venkatasudhahar, Ganesan, Dharmalingam, Tarigonda, Hariprasad

Effect on Ageing and Cerium Addition on Magnesium Alloy

2024-01-5209

12/10/2024

Magnesium (Mg) alloys are becoming ever more ubiquitous as the need for lighter and stronger alloys has increased significantly in the past decades. Mg alloy grade AZ91D is embedded in 0.5 of cerium have a high strength-to-weight ratio and lower specific density, which is useful in the case of automobile applications. An inconclusive study by Lagowski has shown that interrupted age hardening of AZ magnesium alloy increases the yield strength by around 10%. An investigation on the developed AZ91D+0.5Ce alloy subjected to various ageing treatments was carried out in this present study. The various aged samples were investigated by optical microscopy and scanning electron microscopy analysis. The yield strength was also evaluated quantitatively as a function of ageing parameters. A significant increase in yield strength and hardness values was observed in the artificially aged samples due to the precipitation of Mg17Al12 phases.

Venkatesh, R., Manivannan, S., Das, A. Daniel, Mohanavel, Vinayagam, Soudagar, Manzoore Elahi Mohammad

Mechanical Properties of Heat Treated Wrought Steels

J413_202412 (Current)

12/5/2024

The figures in this SAE Information Report illustrate the principle that, regardless of composition, steels of the same cross-sectional hardness produced by tempering after through hardening will have approximately the same longitudinal1 tensile strength at room temperature. Figure 1 shows the relation between hardness and longitudinal tensile strength of 0.30 to 0.50% carbon steels in the fully hardened and tempered, as rolled, normalized, and annealed conditions. Figure 2 showing the relation between longitudinal tensile strength and yield strength, and Figure 3 illustrating longitudinal tensile strength versus reduction of area, are typical of steels in the quenched and tempered condition. Figure 3 shows the direct relationship between ductility and hardness and illustrates the fact that the reduction of area decreases as hardness increases, and that, for a given hardness, the reduction of area is generally higher for alloy steels than for plain carbon steels. It is evident from these curves that steels of the same cross-sectional hardness have about the same strength characteristics, so that any one of several different compositions would yield the same results. For some specific application then, the first thing to be determined is what composition is required to obtain proper hardening in the size section involved. This information is not contained in mechanical property charts, but can be determined from published data or by means of a hardenability test. Methods of making this hardenability test and interpretation of the test results are provided in SAE J406b. Having selected a steel that will through harden in the size section under consideration, the engineer must decide from the service stresses imposed on the finished part what tensile properties are required in the part. These tensile properties may then be converted to hardness values from the figures given here; and from Figure 4 showing the effect of tempering temperature on hardness, the appropriate tempering temperature to obtain this hardness can be selected. In Figure 4 the curves are approximate values to be used as a guide. Carbon steels and lean alloy steels, when fully hardened, will fall slightly below the curves and strongly alloyed steels will fall slightly above the curves. Figure 4 showing the effect of tempering temperature on hardness is a summary of information contained in a large number of mechanical property charts published by steel companies, alloy suppliers, and users. These charts represent, as do the charts on tensile, yield strengths, and reduction of area, data on all SAE alloy and carbon steels with carbon contents of 0.30 to 0.50%. Mechanical property values obtained from these few summary figures will be as accurate as the information formerly available in a large number of charts, each representing an individual type of steel. For more exact information it would be necessary to make tests on samples from individual heats of steel. NOTE—Mechanical properties in this report are monotonic and do not represent cyclic test loading conditions. Cyclic loading and cyclic material properties are described in SAE J1099.

Metals Technical Committee

Steel, Extra High Toughness, Corrosion-Resistant, Bars, Wire, Forgings, Rings, and Extrusions 13Cr - 8.0Ni - 2.2Mo - 1.1Al Vacuum Induction Plus Consumable Electrode Melted, Solution Heat Treated, Precipitation Hardened (H1050)

AMS5934/H1050 (Current)

10/1/2024

This specification covers a corrosion-resistant steel product in the solution and precipitation heat-treated (H1050) condition, 12 inches (305 mm) and under in nominal diameter, thickness, or, for hexagons, least distance between parallel sides.

AMS F Corrosion and Heat Resistant Alloys Committee

Steel, Extra High Toughness, Corrosion-Resistant, Bars, Wire, Forgings, Rings, and Extrusions, 13Cr - 8.0Ni - 2.2Mo - 1.1Al Vacuum Induction Plus Consumable Electrode Melted, Solution Heat Treated, Precipitation Hardened (H950)

AMS5934/H950 (Historical)

8/27/2024

This specification covers a corrosion-resistant steel product in the solution and precipitation heat-treated (H950) condition, 12 inches (305 mm) and under in nominal diameter, thickness, or, for hexagons, least distance between parallel sides.

AMS F Corrosion and Heat Resistant Alloys Committee

AMS5934/H1100 (Current)

8/27/2024

This specification covers a corrosion-resistant steel product in the solution and precipitation heat-treated (H1100) condition, 12 inches (305 mm) and under in nominal diameter, thickness, or, for hexagons, least distance between parallel sides. The aged product may be supplied directly by a producer or by another entity performing the functions of a producer as defined in AS6279. The latter can be accomplished by precipitation heat treatment of solution treated material previously certified to AMS5934. The entity assuming responsibility for the aging operation is designated the producer of AMS5934/H1100.

AMS F Corrosion and Heat Resistant Alloys Committee

AMS5934/H1025 (Current)

8/27/2024

This specification covers a corrosion-resistant steel product in the solution and precipitation heat-treated (H1025) condition, 12 inches (305 mm) and under in nominal diameter, thickness, or, for hexagons, least distance between parallel sides.

AMS F Corrosion and Heat Resistant Alloys Committee

Steel, Extra High Toughness, Corrosion-Resistant, Bars, Wire, Forgings, Rings, and Extrusions 13Cr - 8.0Ni - 2.2Mo - 1.1Al Vacuum Induction Plus Consumable Electrode Melted Solution Heat Treated, Precipitation Hardened (H1150)

AMS5934/H1150 (Current)

8/27/2024

This specification covers a corrosion-resistant steel product in the solution and precipitation heat-treated (H1150) condition, 12 inches (305 mm) and under in nominal diameter, thickness, or, for hexagons, least distance between parallel sides.

AMS F Corrosion and Heat Resistant Alloys Committee

AMS5934/H1000A (Current)

8/19/2024

This specification covers a corrosion-resistant steel product in the solution and precipitation heat treated (H1000) condition, 12 inches (305 mm) and under in nominal diameter, thickness, or, for hexagons, least distance between parallel sides.

AMS F Corrosion and Heat Resistant Alloys Committee

Minimization of High Temperature Oxidation, Aluminum Alloy Heat Treatment

ARP7500 (Current)

7/3/2024

This recommended practice provides recommendations for minimizing high temperature oxidation (HTO) during the heat treatment of aluminum alloy products and parts. HTO leads to deterioration of properties.

AMS D Nonferrous Alloys Committee

Sliding-Window Matrix Pencil Method for Whirl Flutter Bifurcation Analysis

F-0080-2024-1271

5/7/2024

This paper investigates a sliding-window matrix pencil method for predicting flutter points and limit-cycle oscillation amplitudes of nonlinear aeroelastic systems that experience whirl flutter. The approach applies the matrix pencil method to a short time window that slides along the free decay of a quantity of interest, quantifying the variation in the system's recovery rate to equilibrium with amplitude. The recovery rates at each amplitude and various forward speeds are extrapolated to predict the critical forward speed of zero recovery rate at those amplitudes. This process yields a set of limit-cycle oscillation solutions that can be visualized as a bifurcation diagram. The approach is demonstrated using output data from transient simulations of a propeller-nacelle test case with hardening structural nonlinearities. The impact of each parameter in the sliding-window matrix pencil method is first characterized via sensitivity analyses. Next, the bifurcation diagram is predicted using the recovery rates for the optimal parameter values. The results are compared with direct time marching and with the extrapolation of recovery rates estimated from envelope functions. The proposed method accurately captures the bifurcation diagram using two pre-flutter transient simulations with no need for envelope functions. This approach shows promise for output-based bifurcation analysis of nonlinear aeroelastic systems exhibiting limit-cycle oscillations associated with whirl flutter.

Warren, Theodore, Riso, Cristina

Aluminum Alloy, Sheet and Plate, 2.5Mg - 0.25Cr (5052-H32), Strain Hardened, Quarter-Hard, and Stabilized

AMS4016N (Current)

4/25/2024

This specification covers an aluminum alloy in the form of sheet and plate 0.017 to 2.000 inches (0.43 to 50.80 mm), inclusive, in nominal thickness (see 8.6).

AMS D Nonferrous Alloys Committee

Comparison of Bake Hardening Effects on AHSSs and Extruded Aluminum Alloys Applied in BEV Reinforcement Structures

2024-01-2240

4/9/2024

At the dawn of battery electric vehicles (BEVs), protection of automotive battery systems as well as passengers, especially from severe side impact, has become one of the latest and most challenging topics in the BEV crashworthiness designs. Accordingly, two material-selection concepts are being justified by the automotive industry: either heavy-gauge extruded aluminum alloys or light-gauge advanced high-strength steels (AHSSs) shall be the optimal materials to fabricate the reinforcement structures to satisfy both the safety and lightweight requirements. In the meantime, such a justification also motivated an ongoing C-STARTM (Cliffs Steel Tube as Reinforcement) Protection project, in which a series of modularized steel tube assemblies, were demonstrated to be more cost-efficient, sustainable, design-flexible, and manufacturable than the equivalent extruded aluminum alloy beams as BEV reinforcement structures. Tangent to this comparative study, the present work shed some light on the bake hardening (BH) effects during a paint-baking cycle, which was a necessary processing procedure for a body-in-white (BIW), on some representative AHSSs and extruded aluminum alloys via various coupon-level mechanical experiments under precise in-situ strain/displacement and temperature control conditions at multiple strain rates and stress states. The corresponding material mechanisms were also reviewed and explained. Eventually, the test results revealed some tremendously distinct changes induced by the BH effects on the two types of metallic materials: the baking-induced Cottrell atmosphere could effectively enhance the strength without weakening the local ductility of the target AHSS, while the baking-induced precipitation slightly hardened the selected aluminum alloy yet lowered its fracture limit. Such a distinction further indicated the advantages of the AHSSs in this application. The ultimate objective of this work was to provide relative references for future finite element simulations and BEV structural designs.

Hu, Jun, Sun, Yeting, Yu, Miao, Wang, Yu-Wei, Thomas, Grant

Induction Hardening of Steel Parts

AMS2745B (Current)

3/12/2024

This specification defines the requirements for locally hardening steel parts by the induction hardening method.

AMS E Carbon and Low Alloy Steels Committee

Methods of Determining Hardenability of Steels

J406_202402 (Current)

2/23/2024

This SAE Standard prescribes the procedure for making hardenability tests and recording results on shallow and medium hardening steels, but not deep hardening steels that will normally air harden. Included are procedures using the 25 mm (1 in) standard hardenability end-quench specimen for both medium and shallow hardening steels and subsize method for bars less than 32 mm (1-1/4 in) in diameter. Methods for determining case hardenability of carburized steels are given in SAE J1975. Any hardenability test made under other conditions than those given in this document will not be deemed standard and will be subject to agreement between supplier and user. Whenever check tests are made, all laboratories concerned must arrange to use the same alternate procedure with reference to test specimen and method of grinding for hardness testing. For routine testing of the hardenability of successive heats of steel required to have hardenability within certain limits, it is sufficient to designate hardenability simply in terms of distance from the quenched end to the point at which a certain hardness is obtained. This designation may also be adequate for comparing steels of different compositions to see whether they have similar hardenability. Hardenability limits for specifying steel in this manner are obtained by measuring the hardenability of a steel which has proved satisfactory for the use intended. The hardenability test may be used in this way as an empirical test. For new components where manufacturing experience is lacking, hardenability data may be effectively used to estimate the hardness profile provided by any given steel. Attendantly, the ability to predict hardenability from chemical composition has become increasingly important when comparing various steel grades or developing new steels for specific applications. One such procedure is described in Appendix A. Other hardenability prediction methods are available from the selected references in Section 2. However, it should be emphasized that the use of any hardenability prediction procedure does not preclude the importance of conducting Jominy end-quench tests to determine the actual hardenability of any specific grade of steel. Hardenability data may be used to estimate hardnesses obtainable with any steel in new machine parts not yet in production and not similar to any parts on which production experience is available. Various hardenability application methods are described in the selected references, Section 2.1, 23 to 25. It appears none of these methods are precise, but these are often useful for estimation purposes. Final correlation on actual parts is necessary.

Metals Technical Committee

SAE TOMORROW TODAY: Will 2024 Be the Year for AV Commercialization?

134352/9/2024

The commercialization of autonomous vehicles requires proficiency across many domains: engineering, product development, logistics, public policy, and more. But no matter the area of expertise, one theme is constant: safety must come first. But how do you measure AV safety in a tangible and transparent way? Just ask Aurora. As the company approaches their first commercial AV trial run from Dallas to Houston, they are laser focused on achieving their Aurora Driver Ready milestone by validating software, hardening hardware, and closing the Aurora Driver Safety Case, an industry first. At the recent Government/Industry Meeting in Washington, DC, we sat down in-person with Nat Beuse, Chief Safety Officer and member of the US Department of Transportation's Transforming Transportation Advisory Committee, to discuss Aurora's approach to AV safety and why scaling AVs will be a tremendous benefit to society.

Hineman, Marcie

Impact of System Nonlinearities on Output-Based Whirl Flutter Prediction

SM-2024-TVF-5096

2/6/2024

This paper investigates the impact of system nonlinearities on output-based whirl flutter prediction. The investigation considers four widely-used damping identification and extrapolation methods-logarithmic decrement, exponential fit, matrix-pencil estimation, and moving-block analysis-alongside bifurcation forecasting, a recently proposed method. The examined methods are compared by predicting the whirl flutter speed of a propeller-nacelle system with structural nonlinearities using computational output data. The comparisons consider various hardening and softening behaviors, excitation amplitudes, and pre-flutter forward speeds, including values as low as 30% below the flutter point. Results indicate that all methods accurately predict the whirl flutter speed for weak nonlinearities and small-amplitude perturbations. While the first four methods markedly lose accuracy with stronger nonlinear effects, bifurcation forecasting maintains consistent accuracy across all examined conditions, even when significant nonlinearities are present.

Riso, Cristina

Steel, Bars and Forgings and Forging Stock, Nitriding, 1.6Cr - 0.35Mo - 1.1Al (0.38 - 0.43C) (135 Mod), Aircraft Quality, Hardened and Tempered, 112 ksi (772 MPa) Tensile Strength

AMS6472H (Current)

1/1/2024

This specification covers an aircraft-quality, low-alloy steel in the form of heat-treated bars and forgings, and of forging stock.

AMS E Carbon and Low Alloy Steels Committee

A Comparative Analysis on Corrosion Behavior on Precipitation Hardened Stainless Steel Weldments for Car Parts

2023-28-0149

11/10/2023

Precipitation Hardened Stainless Steel (PHSS) is one of the martensitic steels that possess exceptional strength and corrosion resistance. Because of its characteristics, this PHSS is exclusively adopted in numerous engineering uses such as nuclear, chemical and marine industries. Welding is one of the important methods of joining that helps to make weldments with better performance characteristics. Corrosion behaviour is one of the important characteristics that contribute hugely to marine and other corrosion-related environments and also this is the most common problem for most of the manufacturing industries. The goal of this study was to analyze the PHSS weldments’ corrosive behavior and compare it with that of the two commonly used welding processes, namely MIG and TIG. The corrosive properties of the weldments were evaluated using various mediums, such as nitric acid, ferric chloride, and Oxalic acid. The weight loss procedure was utilized to calculate the PHSS weldments’ corrosion rate. The results of the study revealed that the corrosion rate has increased with time. Temperature variations were identified as the primary cause of this phenomenon.

D, Palanisamy, A, Gnanarathinam, Pasupuleti, Thejasree, Natarajan, Manikandan, Kiruthika, Jothi, Polanki, Vamsinath

Steel Bars 0.95Cr - 0.20Mo (0.28 to 0.33C) (SAE 4130) Aircraft Quality Hardened and Tempered, 125 ksi (862 MPa) Tensile Strength

AMS6346D (Current)

10/16/2023

This specification covers an aircraft-quality, low-alloy steel in the form of heat-treated bars 1.50 inches (38.1 mm) and less in diameter or least distance between parallel sides.

AMS E Carbon and Low Alloy Steels Committee

Self-Sensing Electric Artificial Muscles

TBMG-48928

9/1/2023

Muscle contraction hardening is not only essential for enhancing strength but also enables rapid reactions in living organisms. Taking inspiration from nature, the team of researchers at Queen Mary’s School of Engineering and Materials Science has successfully created an artificial muscle that seamlessly transitions between soft and hard states while also possessing the remarkable ability to sense forces and deformations.

Development and Performance Studies of a Lightweight AA6061/Ti Particulate Surface Composite through Friction Stir Processing

2023-28-1303

5/25/2023

Surface engineering is becoming increasingly crucial for several automotive and aerospace components that involve intense surface interactions. Friction stir processing (FSP) has emerged as an effective surface modification and hardening technique in recent days. The technique also allows the incorporation of reinforcement into the modified surface to enhance the strength and hardness further. This work applied FSP to develop a pure Ti particulate reinforced AA6061 metal matrix composite (MMC). Six different strategies were adapted (in the form of micro grooves, micro drills on the surface) to effectively infuse reinforcement on the alloy surface. Microstructural changes before and after FSP were studied using SEM and EBSD. Other tests such as post-mortem EDS, XRD, hardness, and compression were also done to examine the performance of developed composite. Microstructural lineaments revealed a more uniform dispersion of reinforcement particles in the matrix when the particles were impregnated using a multi-groove approach. Details on the development strategy, microstructural evolution and various strengthening mechanisms involved in enhancing the mechanical properties are presented in this manuscript.

Hussain, Ilyas, Immanuel, Jose

Effect of Varying Levels of Work Hardening and Bake Hardening on the Mechanical Properties of Dual Phase Steels

2023-28-1331

5/25/2023

In most cases, the properties of a metal are evaluated in their as rolled condition, prior to any work hardening or bake hardening. But in the Automotive World, these steels get work hardened during the forming process and bake hardened in the paint shop. The goal of this paper is to evaluate the variations in the performance of Dual Phase (DP) steels and understand the most optimized method of testing and property generation. This method can then be used to extrapolate to real automotive components. Dual Phase Steels or DP Steels contain a mixture of Ferrite & Martensite from which they derive their name. They are a part of the advanced high strength and ultra-high strength steels steel family according to World Auto Steels. The Ferrite phase, with its iron content contributes to the material displaying an increased level of ductility whilst, the martensitic phase provides the steel with increased mechanical strength. These two properties together enable the steel to be highly desirable in the automotive industry with varying uses from being used as Body Panels to Crash critical components. These two critical part sets of the vehicle are often heavily simulated and tested. Over the course of this paper, we will try to understand the effects of work hardening, also referred to as Pre-Straining and bake hardening on two popularly used DP Steels. DP grade steels, ISC590Y and ISC780Y were used for the study. The aim of the study is to understand the effect of bake hardening, effect varying levels of work hardening and bake hardening on these steels and correlate it to the base data which is used in simulations. It is also important to try and understand the optimum degree of work hardening that might be required to gain the most out of these steels.

Vegi, Nischay, Ragothaman, Balakrishnan

Methods of Measuring Case Depth

J423_202305 (Current)

5/22/2023

Case hardening may be defined as a process for hardening a ferrous material in such a manner that the surface layer, known as the case, is substantially harder than the remaining material, known as the core. The process embraces carburizing, nitriding, carbonitriding, cyaniding, induction, and flame hardening. In every instance, chemical composition, mechanical properties, or both are affected by such practice. This testing procedure describes various methods for measuring the depth to which change has been made in either chemical composition or mechanical properties. Each procedure has its own area of application established through proved practice, and no single method is advocated for all purposes. Methods employed for determining the depth of case are either chemical, mechanical, or visual, and the specimens or parts may be subjected to the described test either in the soft or hardened condition. The measured case depth may then be reported as either effective or total case depth on hardened specimens, and as total case depth on unhardened specimens. It should be recognized that the relationship between case depths as determined by the different methods can vary extensively. Factors affecting this relationship include case characteristics, parent steel composition, quenching conditions, and others. It is not possible to predict, in some instances for example, effective case depth by chemical or visual means. It is important, therefore, that the method of case depth determination be carefully selected on the basis of specific requirements, consistent with economy.

Metals Technical Committee

Prediction of Surface Finish on Hardened Bearing Steel Machined by Ceramic Cutting Tool

05-16-03-0021

5/17/2023

Prediction of the surface finish of hardened bearing steels was estimated in machining with ceramic uncoated cutting tools under various process parameters using two statistical approaches. A second-order (quadratic) regression model (MQR, multiple quantile regression) for the surface finish was developed and then compared with the artificial neural network (ANN) method based on the coefficient determination (R 2), root mean square error (RMSE), and percentage error (PE). The experimental results exhibited that cutting speed was the dominant parameter, but feed rate and depth of cut were insignificant in terms of the Pareto chart and analysis of variance (ANOVA). The optimum surface finish in machining bearing steel was achieved at 100 m/min speed, 0.1 mm/revolution (rev) feed rate, and 0.6 mm depth of cut. In addition, the ANN model revealed a better performance than that of MQR for predicting the surface finish when machining the hardened bearing steels because R 2 was about 0.787 and 0.903 for MQR and ANN, respectively. Besides, these were associated with RMSE of 0.302 and 0.1071 for MQR and ANN. Further, PE estimated from randomly selected data were about 25.56% and 10.86% for MQR and ANN, respectively. However, MQR presented the lowest error of 2.86%, but the highest error of 40.3%, while ANN indicated the lowest error of 0.11%, but the highest error of 37.0%, respectively.

Şahin, Yusuf

Design of a Test Geometry to Characterize Sheared Edge Fracture in a Uniaxial Bending Mode

2023-01-0730

4/11/2023

The characterization of sheet metals under in-plane uniaxial bending is challenging due to the aspect ratios involved that can cause buckling. Anti-buckling plates can be employed but require compensation for contact pressure and friction effects. Recently, a novel in-plane bending fixture was developed to allow for unconstrained sample rotation that does not require an anti-buckling device. The objective of the present study is to design the sample geometry for sheared edge fracture characterization under in-plane bending along with a methodology to resolve the strains exactly at the edge. A series of virtual experiments were conducted for a 1.0 mm thick model material with different hardening rates to identify the influence of gage section length, height, and the radius of the transition region on the bend ratio and potential for buckling. Two specimen geometries are proposed with one suited for constitutive characterization and the other for sheared edge fracture. It is shown that the local strains at the edge can be accurately resolved using basic image processing without the need for digital image correlation that cannot resolve the strain field at the edge. Finally, a technique to evaluate the location of the unstretched fibre is considered to determine the strain distribution across the gage width for use in constitutive characterization under bending.

Narayanan, Advaith, Butcher, Cliff

Effect of Pre-Strain and Baking Temperature on Bake-Hardening Behaviour of BH220 Steel

2023-01-0078

4/11/2023

Light weighting has been one of major driver in automotive industry for few decades. Today when automobile industry is in the transition from internal combustion engine to electric vehicles it becomes even more dominant driver. Many high strength or advanced high strength steels are used in different parts of automotive body for down-gauging and light weighting. BH 220 steel is used in automotive skin panels for its bake hardening property. BH220 provides excellent combination of formability during stamping process and dent resistance in skin panel parts post painting and baking cycle. This material uses CED oven temperature for baking and provide bake hardening effect (BH effect/BH Index) in parts due to increase in yield strength by 35-70 MPa. Current national and international standards specify requirement on BH Index at 170°C for 20 minutes with 2% pre-strain. In order to optimize paint shop CED oven baking temperature, study carried out to know baking temperature effect on BH Index at different pre-strain. In this study effect of baking temperature & %pre-strain on BH Index is studied. For Bake hardening study, tensile samples are prepared, pre-strained to 0, 0.5,1 and 2 % and subjected to bake hardening at different temperature in 130-170°C range for 20 minutes. Tensile testing is performed to evaluate BH Index for these samples. Based on study empirical relation is generated, that can provide BH Index on different baking temperature. The result shows increase in BH Index with same pre-strain however rate of increment is less post 150°C baking temperature. Additionally, BH Index reduces with increase in pre-strain with same baking temperature.

Jain, Vikas, Misal, Swapnali, Paliwal, Lokesh, Sathaye, Asmita

Shot Peening Coverage Determination

J2277_202301 (Current)

1/13/2023

This SAE Recommended Practice provides procedures for determining shot peening coverage and relating coverage to part exposure to the media stream. Effectiveness of shot peening is directly dependent on coverage. Inadequate or excessive coverage can be detrimental to fatigue strength and component life.

Surface Enhancement Committee

Steel, Sheet, Strip, and Plate 0.75Cr - 9.0Ni - 4.5Co - 1.0Mo - 0.09V (0.17 - 0.23C) Vacuum Consumable Electrode Melted, Annealed

AMS6523J (Current)

11/2/2022

This specification covers a premium aircraft-quality, low-alloy steel in the form of sheet, strip, and plate.

AMS E Carbon and Low Alloy Steels Committee

Steel, Corrosion-Resistant, Bars, Wire, Forgings, Rings, and Extrusions 15Cr - 4.5Ni - 0.30Cb (Nb) - 3.5Cu Solution and Precipitation Heat Treated (H900)

AMS5659/H900 (Historical)

9/14/2022

This specification covers a corrosion-resistant steel product 12 inches (305 mm) and under in nominal diameter, thickness or, for hexagons, least distance between parallel sides, and having a maximum cross-sectional area of 144 in2 (930 cm2) in the solution and precipitation heat treated (H900) condition.

AMS F Corrosion and Heat Resistant Alloys Committee

Steel, Corrosion-Resistant, Bars, Wire, Forgings, Rings, and Extrusions 15Cr - 4.5Ni - 0.30Cb (Nb) - 3.5Cu Solution and Precipitation Heat Treated (H925)

AMS5659/H925 (Historical)

9/14/2022

This specification covers a corrosion-resistant steel product 12 inches (305 mm) and under in nominal diameter, thickness or, for hexagons, least distance between parallel sides, and having a maximum cross-sectional area of 144 square inches (93 cm2) in the solution and precipitation heat treated (H925) condition.

AMS F Corrosion and Heat Resistant Alloys Committee

Steel, Corrosion-Resistant, Bars, Wire, Forgings, Rings, and Extrusions 15Cr - 4.5Ni - 0.30Cb (Nb) - 3.5Cu Consumable Remelted, Solution and Precipitation Heat Treated (H1025)

AMS5659/H1025C (Current)

9/14/2022

This specification covers a corrosion-resistant steel product 12 inches (305 mm) and under in nominal diameter, thickness or for hexagons, least distance between parallel sides, and having a maximum cross sectional area of 144 square inches (930 cm2) in the solution and precipitation heat treated (H1025) condition.

AMS F Corrosion and Heat Resistant Alloys Committee

Steel, Corrosion-Resistant, Bars, Wire, Forgings, Rings, and Extrusions 15Cr - 4.5Ni - 0.30Cb (Nb) - 3.5Cu Solution and Precipitation Heat Treated (H1150)

AMS5659/H1150 (Current)

9/14/2022

This specification covers a corrosion-resistant steel product 12 inches (305 mm) and under in nominal diameter, thickness or for hexagons, least distance between parallel sides, and having a maximum cross-sectional area of 144 square inches (930 cm2) in the solution and precipitation heat treated (H1150) condition.

AMS F Corrosion and Heat Resistant Alloys Committee

Steel, Corrosion-Resistant, Bars, Wire, Forgings, Rings, and Extrusions 15Cr - 4.5Ni - 0.30Cb (Nb) - 3.5Cu Solution and Precipitation Heat Treated (H1100)

AMS5659/H1100 (Current)

9/14/2022

This specification covers a corrosion-resistant steel product 12 inches (305 mm) and under in nominal diameter, thickness or for hexagons, least distance between parallel sides, and having a maximum cross-sectional area of 144 square inches (930 cm2) in the solution and precipitation heat treated (H1100) condition.

AMS F Corrosion and Heat Resistant Alloys Committee

Steel, Corrosion-Resistant, Bars, Wire, Forgings, Rings, and Extrusions 15Cr - 4.5Ni - 0.30Cb (Nb) - 3.5Cu Solution and Precipitation Heat Treated (H1075)

AMS5659/H1075 (Current)

9/14/2022

This specification covers a corrosion-resistant steel product 12 inches (305 mm) and under in nominal diameter, thickness or for hexagons, least distance between parallel sides, and having a maximum cross-sectional area of 144 square inches (930 cm2) in the solution and precipitation heat treated (H1075) condition.

AMS F Corrosion and Heat Resistant Alloys Committee

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