Browse Topic: Ferrous metals
The development of advanced high-strength steels has become essential in the production of lightweight, safe, and more economical vehicles within the context of the automotive industry. Among the advanced high-strength steels, complex phase steels stand out, characterized by their high formability and high energy absorption and deformation capacity. Laser welding is a technique that applies laser using high energy density as a heat source. It has the advantages that the high welding speed and low heat input compared to other welding methods cause a decrease in deformation, and the narrow width of the weld bead and heat-affected zone allows for the welding of complex parts that would be difficult for other welding methods. Based on a study of a complex phase steel, an analysis was made of the microstructures observed by optical microscopy, the grain boundaries and certain phases contained in this microstructure, as well as the microstructures of each area in the laser welding region
The properties of organic nitrate ester that inhibit scale formation were investigated in order to acquire a better understanding of ferrous carbide precipitation from supersaturated solutions. When the scale inhibitor was present, precipitation rates were much lower than when it was missing, even at very low concentrations. When the temperature and time are increased simultaneously, more scale is deposited. The effect of nitrate ester on scale deposition demonstrates that the inhibitory dosage is relatively low at low temperatures but rapidly increases when exposed to high temperatures. The inhibitor is thought to alter the shape of the first crystals by binding to dynamic growth sites and inhibiting the threshold level of development
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
This specification covers an aircraft-quality, low-alloy steel in the form of sheet, strip, and plate
This specification covers established inch/pound manufacturing tolerances applicable to carbon steel bars ordered to inch/pound dimensions. These tolerances apply to all conditions, unless otherwise noted. The term “excl” applies only to the higher figure of the specified range
This specification covers an aircraft-quality, low-alloy steel in the form of bars, forgings, mechanical tubing, and forging stock
This specification covers an aircraft-quality nitriding grade low-alloy steel in the form of bars, forgings, mechanical tubing, and forging stock
This specification covers a carbon steel in the form of sheet and strip
This SAE Information Report summarizes the characteristics of carburized steels and factors involved in controlling hardness, microstructure, and residual stress. Methods of determining case hardenability are reviewed, as well as methods to test for freedom from non-martensitic structures in the carburized case. Factors influencing case hardenability are also reviewed. Methods of predicting case hardenability are included, with examples of calculations for several standard carburizing steels. A bibliography is included in 2.2. The references provide more detailed information on the topics discussed in this document
ABSTRACT This paper addresses candidate technologies for attaching steels to selected lightweight materials. Materials of interest here include aluminum and titanium alloys. Metallurgical challenges for the aluminum-to-steel and titanium-to-steel combinations are first described, as well as paths to overcome these challenges. Specific joining approaches incorporating these paths are then outlined with examples for specific processes. For aluminum-to-steel joining, inertia, linear, and friction stir welding are investigated. Key elements of success included rapid thermal cycles and an appropriate topography on the steel surface. For titanium-to-steel joining, successful approaches incorporated thin refractory metal interlayers that prevented intimate contact of the parent metal species. Specific welding methods employed included resistance mash seam and upset welding. In both cases, the process provided both heat for joining and a relatively simple strain path that allowed significant
ABSTRACT Flash® Bainite Processing employs rapid thermal cycling (<10s) to strengthen commercial off the shelf (COTS) steel sheet, plate, and tubing into Ultra Hard 600 Armor, High Hard 500 Armor, and advanced high strength steel (AHSS). In a continuous process, induction technology heats a narrow segment of the steel cross section in just seconds to atypically high temperature (1000-1300°C). Quenching substantially immediately follows. A report by Benet Labs and Picatinny Arsenal, investigating a less mature flash technology in 2011, surmised that the novel flash bainite process for steels has the potential to reduce cost and weight while also enhancing mechanical performance [1]. Receiving five financial grants, the US Dept of Energy has greatly matured flash technology in the last few years and its metallurgical understanding in collaboration with Oak Ridge National Lab and others. DOE has named Flash Bainite as the “SBIR Small Business of the Year” in May 2018 and awarded a Phase 3
ABSTRACT V-shaped hulls for vehicles, to mitigate buried blast loads, are typically formed by bending plate. Such an approach was carried out in fabricating small test articles and testing them with buried-explosive blast load in Southwest Research Institute’s (SwRI) Landmine Test Fixture. During the experiments, detailed time dependent deflections were recorded over a wide area of the test article surface using the Dynamic Deformation Instrumentation System (DDIS). This information allowed detailed comparison with numerical simulations that were performed with LS-DYNA. Though in general there is good agreement on the deflection, in the specific location of the bends in the steel the agreement decreases in the lateral cross section. Computations performed with empirical blast loads developed by SwRI and by more computationally intensive ALE methods in LS-DYNA produced the same results. Computations performed in EPIC showed the same result. The metal plate was then bent numerically so
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