The SAE MOBILUS platform will continue to be accessible and populated with high quality technical content during the coronavirus (COVID-19) pandemic. x

Your Selections

Corrosion
Show Only

Collections

File Formats

Content Types

Dates

Sectors

Topics

Authors

Publishers

Affiliations

Committees

Events

Magazine

   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Use of Nitric Acid to Control the NO2:NOX Ratio Within the Exhaust Composition Transient Operation Laboratory Exhaust Stream

Southwest Research Institute-Robert Henderson, Ryan Hartley, Cary Henry
  • Technical Paper
  • 2020-01-0371
To be published on 2020-04-14 by SAE International in United States
The Exhaust Composition Transient Operation Laboratory (ECTO-Lab) is a burner system developed at Southwest Research Institute (SwRI) for simulation of IC engine exhaust. The current system design requires metering and combustion of nitromethane in conjunction with the primary fuel source as the means of NOX generation. While this method affords highly tunable NOX concentrations even over transient cycles, no method is currently in place for dictating the speciation of nitric oxide (NO) and nitrogen dioxide (NO2) that constitute the NOX mixture. NOX generated through combustion of nitromethane is dominated by NO, and generally results in a NO2:NOX ratio of <5 %. Generation of any appreciable quantities of NO2 is therefore dependent on an oxidation catalyst to oxidize a fraction of the NO to NO2. Presented within this manuscript is a method for precise control of the NO2:NOX ratio within the ECTO-Lab exhaust stream by using nitric acid as the NOX precursor molecule in lieu of nitromethane. While decomposition of nitromethane generates NO as the dominate component of the NOX mixture, nitric acid decomposition produces primarily…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Spatially Optimized Diffusion Alloys: A Novel Multi-Layered Steel Material for Exhaust Applications

Arcanum Alloys Inc.-Zachary Detweiler, David Keifer, Daniel Bullard
Tenneco Inc.-Adam Kotrba, Tony Quan, Winston Wei
  • Technical Paper
  • 2020-01-1051
To be published on 2020-04-14 by SAE International in United States
A novel Spatially Optimized Diffusion Alloy (SODA) material has been developed and applied to exhaust systems, a very aggressive environment with high temperatures and loads, as well as excessive corrosion. Traditional stainless steels disperse chromium homogeneously throughout the material, with varying amounts ranging from 11% to 18% dependent upon its grade (e.g. 409, 436, 439, and 441). SODA steels, however, offer layered concentrations of chromium, enabling an increased amount along the outer surface for much needed corrosion resistance and aesthetics. This outer layer, approximately 70µm thick, exceeds 20% of chromium concentration locally, but is only 3% in bulk, offering selective placement of the chromium to minimize its overall usage. And, since this layer is metallurgically bonded, it cannot delaminate or separate from its core, enabling durable protection throughout manufacturing processes and full useful life. The core material may be of various grades, however, so this study employs interstitial free steel (low carbon), which offers not only commercial advantages, but also eases manufacturing operations, as it is more formable than stainless steel grades. The material and…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Thermo-mechanical Fatigue and Life Prediction of Turbocharged Engine Cylinder Head

SAIC Motor Technical Center-Yang Jun Wang, Zheng Xu, Ming Chen
  • Technical Paper
  • 2020-01-1163
To be published on 2020-04-14 by SAE International in United States
In order to predict more accurately the cracking failure of cylinder head during the durability test of turbocharged engine in the development, a comprehensive evaluation method of cylinder head durability is established. In this method, both high cycle and low cycle fatigue performance are calculated, and the results are combined statistically using weighted algorithm to provide failure assessment. The method is then applied to investigate the root cause of cracking of cylinder head and assess design optimizations. Multidisciplinary approach is adopted to optimize high cycle fatigue and low cycle fatigue performance simultaneously to achieve the best comprehensive performance. In this paper, the details of the method development are described. First, the high cycle and low cycle fatigue properties of cylinder head materials were measured at different temperatures, and the fatigue life and high temperature creep properties of materials under thermo-mechanical fatigue cycle were also tested. These material properties provide basis for accurate simulations. For the low cycle fatigue analysis model, a thermal shock cycle same as dyno test is simulated using transient method, which accurately…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Interactive Effects between Sheet Steel, Lubricant and Measurement System

General Motors LLC-Jatinder P. Singh
University of Colorado Denver-Luis Rafael Sanchez Vega, Eduardo Corral
  • Technical Paper
  • 2020-01-0755
To be published on 2020-04-14 by SAE International in United States
This study assessed the interaction between sheet steel, lubricant and measurement system under typical sheet forming conditions. Deep Drawing Quality Bare, Electrogalvanized and Hot Dip Galvanized mild sheet steel, were tested under a Draw Bead Simulator (DBS). Lubricant conditions varied from thoroughly dry (0% lube) to overlubricated (>6 g/m2); with 1g of lubricant per m2 as the target of general usage. Mixed lubrication cases, with incremental amounts of a lubricant applied over an existing base of 1 g/m2 rust protection oil, were analyzed. The results show distinctive differences and similarities on friction between the bare material and the coatings. While friction on the bare substrate was higher than the coatings under lubricated conditions, it was significantly more tolerant to dry conditions. Stick-slip behavior was studied as a measurement system response to intermittent friction between the testing tools. These measurement test responses, and sheet surface texture changes during testing were discussed.
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Microstructure-Fatigue Property Relationships for Cast Irons

National Research Council (Canada)-Xijia Wu
  • Technical Paper
  • 2020-01-0187
To be published on 2020-04-14 by SAE International in United States
Cast irons are widely used for combustion engine/exhaust system applications, not only because they are less expensive but also because they offer some attractive properties such as good thermal conductivity, relatively high specific yield strength, and good oxidation resistance. Cast irons can be made with a wide variety of microstructures containing either flake-like graphite (FG), nodular graphite (NG) or vermicular graphite (VG), or mixing of the above, which control their mechanical and fatigue properties. In this paper, a microstructure-fatigue property relationship model is developed, combining the Tanaka-Mura-Wu’s fatigue crack nucleation model with Eshelby’s solution for materials containing ellipsoidal inclusions. This applies to cast irons considering its microstructural graphite characters (shape, size, elastic modulus and Poisson’s ratio). This model is used to analyse ductile cast iron (DCI) with nodular graphite (NG) microstructure, grey cast iron (GCI) with flake-like graphite (FG) microstructure, and compacted graphite iron (CGI) with vermicular graphite (VG) microstructure. Excellent agreement is found between the model prediction and the experimental data or the Coffin-Manson-Basquin correlations at room temperature. Further development will be to incorporate…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Crevice Corrosion Accelerated Test for Cylinder Head/Gasket/Monoblock Assemblies from Lightweight Engines Exposed to Overheating Cycles

Instituto Politecnico Nacional Esime Zac-Gerardo Rodríguez-Bravo, Roberto Vega-Moron
Instituto Politécnico Nacional ESIQIE-Jesús Godínez-Salcedo
  • Technical Paper
  • 2020-01-1067
To be published on 2020-04-14 by SAE International in United States
Severe crevice corrosion occurring at the joint of cylinder head/gasket/mono-block from lightweight engines causes accelerated dissolution of lightweight material, in particular, in cylinder head producing the linking of the cooling vessels with the combustion chambers or oil vessels. It is conductive to combustion of coolant or oil, and contamination of oil with coolant or vice versa, which is considered as catastrophic engine failure. Since crevice corrosion is dependent of many of the actual assembly characteristics, coolant and engine operation conditions, full-scale tests are the most frequent alternative for this type of evaluations. Nonetheless, they are very long and expensive, and sometimes, unreliable tests. Alternatively, the standard procedure ASTM-G78 is widely used to evaluate crevice corrosion propensity of different metallic materials under certain specified conditions trough immersion tests in a corrosive media in shorter test times. However, the method does not cover the characteristics and conditions existing at the cylinder head/gasket/mono-block joint. Hence, this paper presents an accelerated test consisting on three-electrode cyclic potentiodynamic anodic polarization and polarization resistance standard trials using special assembly samples to…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

The role of NOx in engine lubricant oxidation

Infineum UK, Ltd.-David R. Coultas
  • Technical Paper
  • 2020-01-1427
To be published on 2020-04-14 by SAE International in United States
Engine technology trends like downsizing, direct injection and effective lean NOx aftertreatment have created challenging environments for lubricating oils. Longer contact times of the lubricant with fuel and NOx, higher sump temperatures and higher NOx levels in blow-by gas promote nitration-oxidation driven by the action of NOx and air on hydrocarbons. Nitration-oxidation has often been overlooked as a mechanism of oil oxidation in real world engines. Indeed, the emphasis is almost exclusively on iron catalysed oxidation in bench tests purporting to protect modern engines against lubricant oxidation. This paper will demonstrate that a proprietary bench nitration-oxidation test is capable of reproducing trends in nitrate ester formation and consumption seen in real engines, which also fully explain the resulting impact on lubricant oxidation without the use of iron catalysts.
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Development of a novel method to simulate cavity preservation in automotive industry

ESS Engineering Software Steyr-Martin Schifko, Kevin Verma, Muraleekrishnan Menon, Vishal NAIR
ESS Gmbh-Bhargav Krishna Chitneedi
  • Technical Paper
  • 2020-01-0900
To be published on 2020-04-14 by SAE International in United States
Corrosion protection is a major topic of research for automotive manufacturers and major suppliers. The most critical parts affected by corrosion are the pillars and cavities. Automotive manufacturers spend a lot of effort to improve protection layers as much as possible to increase the longevity of their products. The Electro-Coat Paint Operation (ELPO) or E-Coat process is key in achieving this goal. Unfortunately, often the electric current does not reach all the areas very well and resulting in undercoating. Also, the consequent baking process might see the ovens not achieving the desired temperatures into the cavities. As a fact it often happens that these areas are exposed by undercoating, and hence undermining the quality of corrosion protection. Some car manufacturers investigate one level more to assure a good quality of corrosion protection also within cavities, by applying wax. This wax coating process aims to cover all problematic areas in a way to make cavities more resistant to unfriendly conditions such as rain, snow, and salt. At present, waxing solves those problems quite well. However, wax…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Elucidation of the Sulfide Corrosion Mechanism in Piston Pin Bushings

Honda R&D Co., Ltd.-Ryuta Motani, Kazuki Maeyama, Kenta Yoshii, Shinji Oshida, Hiroki Masuda, Tomohiro Ikeda, Tatsuya Okayama, Shinichi Takahashi
  • Technical Paper
  • 2020-01-1079
To be published on 2020-04-14 by SAE International in United States
Today, downsizing is realizing lighter and more compact engines, but at the same time, the use of turbochargers and other supercharging devices in order to supplement power and torque is increasing their power density, resulting in higher thermal and mechanical loads. In such environment, corrosion of the copper alloy bushes (piston pin bushes) that are press-fitted into the small ends of the conrods is becoming an issue. It is known that automotive bearing materials such as bushes suffer sulfidation corrosion as a result of reacting with an extreme-pressure additive (Zn-DTP) in the lubricating oil, but the reaction paths remain unclear. The research discussed in this paper therefore tried to elucidate the reaction paths in the reaction between Zn-DTP and copper in actual vehicle environments. Unit corrosion tests were conducted in order to identify the effect of the state of degradation of the oil and its temperature and copper content on corrosion. The results of these tests suggested that the direct reaction between copper and Zn-DTP was not the main factor in the corrosion under study,…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Understanding vapor and solution phase corrosion of lubricants used in electrified transmissions

Lubrizol-Gregory Hunt, Christopher Prengaman
  • Technical Paper
  • 2020-01-0561
To be published on 2020-04-14 by SAE International in United States
In this study, the corrosion rates of commercially available lubricants that are found in electrified and conventional transmissions are measured in the vapor and solution phase across a range of operating temperatures using the wire corrosion test. The results of this study demonstrate the importance of performing vapor and solution phase corrosion measurements in real time across a range of temperatures and offers an efficient and cost-effective way to screen fluid chemistries over a range of potential corrosion situations. Corrosion measurements such as these, when interpreted correctly provide reliable data on which to base appropriate safety margins during the design phase.