Criteria

Text:
Topic:
Display:

Results

Viewing 1 to 30 of 6921
2016-04-13
Event
This symposium provides a forum for researchers and application engineers to disseminate the knowledge and information gained in the area of advanced high-strength and press-hardening steel development and applications in automotive structures, enabling light-weight and durable vehicles with improved safety.
2016-04-13
Event
This symposium provides a forum for researchers and application engineers to disseminate the knowledge and information gained in the area of advanced high-strength and press-hardening steel development and applications in automotive structures, enabling light-weight and durable vehicles with improved safety.
2016-04-05
Technical Paper
2016-01-0355
Takashi Iwama
Dent resistance and surface distortion were deteriorated by reduction of outer panel thickness. While aluminum or resin use for outer panel are increasing, it is not spread in the car of cost low price, steel is used. However, even in vehicles of lower price it has been required weight reduction of body, weight reduction has become necessary with steel using. Therefore, it becomes difficult to reduce automotive body weight. To investigate the weight reduction potential with steel using, effective factors on surface distortion and dent resistance properties were evaluated quantitatively with the aim of securing these properties. Materials used for experiment were tensile strength(TS) 340 MPa grade bake hardenable (BH) steel sheet, which is often used in the door outer and TS 440 MPa grade BH steel sheet for outer panel which developed by JFE Steel.
2016-04-05
Technical Paper
2016-01-0380
Ghassan Abed, Yung-Li Lee, Jian Zhu
Two popular critical plane models developed by Fatemi-Socie and Smith-Watson-Topper were derived from the experimental observations of the nucleation and growth of cracks during loading. The Fatemi-Socie critical plane model is applicable for the life prediction of materials for which the dominant failure mechanism is shear crack nucleation and growth, while the Smith-Watson-Topper model, for materials that fail predominantly by crack growth on planes perpendicular to the planes of maximum tensile strain or stress. The two critical plane models have been validated primarily by in-phase and 90° out-of-phase loading, and few, on the complex, non-proportional loading paths. A successful critical plane model should be able to predict both the fatigue life and the dominant failure planes. However, some experimental studies indicate the 304 stainless steel has the two possible failure modes, shear and tensile failure dominant, depending on the loading mode and stress and strain states.
2016-04-05
Technical Paper
2016-01-0358
Saeid Nasheralahkami, Sergey Golovashchenko, Kaicen Pan, Lindsay Brown, Bindiya Gugnani
In recent years, implementation of advanced high strength steels (AHSS) such as dual phase steels (DP) are increasing in automotive components due to their superior structural performance and vehicle weight reduction capabilities. However, these materials are often sensitive to trimmed edge cracking if stretching along sheared edge occurs in such processes as stretch flanging. Tool wear is another major issue in the trimming of AHSS because of higher contact pressures at the interface between the cutting edges of the trimming die and sheet metal blank defined by AHSS higher flow stresses. Another reason for tool wear is presence of martensitic particles on the surface of the blank. The objective of the present paper is to study the influence of trimming conditions and tool wear on quality and stretchability of trimmed edge of DP980 steel sheet.
2016-04-05
Technical Paper
2016-01-0357
Daniel J. Branagan, Andrew E. Frerichs, Brian E. Meacham, Sheng Cheng, Alla V. Sergueeva
The historical development of autobody steels has demonstrated a paradoxical relationship between strength and ductility, with increasing strength necessary for lightweighting commensurate with reductions in ductility necessary for cold formability. This in turn creates geometric constraints in part design and manufacturing, ultimately limiting usage of these higher strength steel grades in automobiles. Attempts to overcome this paradox have focused on quench and tempering including variants such as quench, partitioning, and tempering to increase strength and three distinct deformation mechanisms including; 1) shear band induced plasticity (SIP), 2) transformation induced plasticity (TRIP), and 3) twinning induced plasticity (TWIP) to increase ductility.
2016-04-05
Technical Paper
2016-01-0392
HongTae Kang, Abolhassan Khosrovaneh, Xuming Su, Mingchao Guo, Yung-Li Lee, Sai Boorgu, Chonghua Jiang
Joining technology is a key factor to utilize dissimilar materials in vehicle structures. Adaptable insert weld (AIW) technology is developed to join sheet steel (HSLA350) to cast magnesium alloy (AM60). The joint is constructed by combining riveting technology and electrical resistance spot welding technology. This joint technology is applied to construct front shock tower structures composed with HSLA350, AM60, and Al6082. This paper is to develop fatigue life prediction methods for AIW using finite element (FE) techniques. First lap-shear and cross-tension specimens were constructed to characterize the fatigue properties of AIW joint. In FE models of the specimen geometry, the AIW joint was represented with two different methods as area contact method (ACM) and with TIE contact method.
2016-04-05
Journal Article
2016-01-0354
Ryoji Suzuki, Yukihide Yokoyama, Takeo Shibano, Tatsuki Sugiura, Noriaki Katori
For commercial vehicles, the globalization is leading to greater demand for stainless steel and austenite stainless steels are mainly used in locations with strict corrosion resistance requirements. This paper shows corrosion resistance superior to that of JIS SUS316L was achieved by applying an electropolishing treatment to low-cost ferritic stainless steel immersed in a nitric acid aqueous solution. As for corrosion tests, the JIS SUS436L ferritic stainless steels were subjected to electropolishing in a nitric acid solution, and then evaluated in corrosion solutions. Their corrosion resistance was then compared to that of SUS316L. and then a significant improvement in corrosion resistance was observed in SUS436L, which was subjected to nitric acid electropolishing.
2016-04-05
Journal Article
2016-01-0361
Takeki Matsumoto, Nan Li, Xin Shi, Jianguo Lin
To reduce the fuel consumption as well as to improve the crash safety of vehicles, the usage of hot stamping parts is increasing dramatically in recent years. Aisin Takaoka has produced hot stamping parts since 2001 and has developed various technologies related to Hot Stamping. In an actual hot stamping process, occasionally low strength parts have been obtained even in the proper forming conditions at prototyping phase. In order to understand these phenomena, phase transformations of boron steel during various cooling rate are investigated within the effects of isothermal strain conditions. The uniaxial tensile test with 1.6mm thickness 22MnB5 specimen at strain rates of 0.1-5.0/s, strain level of 0-0.3 and strain applied temperature of 650-800°C are conducted. Dilatometer is used to measure the dimensional changes of the specimen to realize the phase transformation.
2016-04-05
Journal Article
2016-01-0360
Cédric Georges, Xavier Vanden Eynde, Frank Goodwin
Advanced high strength steels used in automotive body and structure applications are exposed to hydrogen during several steps of their processing. For galvanized sheet steel, one of these is the continuous galvanizing process, during which the sheet is prepared for coating in a H2-N2 furnace. This paper shows the relationship between hydrogen uptake in DP600 and DP980 grades, together with an IF steel control composition, and galvanizing process conditions. Hydrogen uptake is strongly dependent on furnace atmosphere and the amount of martensite in the steel but has little dependence on soaking time, humidity of the furnace atmosphere, or temperature within the usual intercritical annealing range. Rapid outgassing was observed during overageing prior to zinc dipping. Slow strain rate tests showed that there was no loss of ductility in galvanized samples that had been treated in a 5% H2 atmosphere or that had been overaged before galvanizing.
2016-04-05
Journal Article
2016-01-0359
Jeff Wang, Charles Enloe, Jatinder Singh, Curt Horvath
Impact toughness (or resistance to fracture) is a critical material property for press hardened steel because hot-formed steel components are often used to construct the safety cage of vehicle body structures. Prior austenite grain size, as controlled by the hot stamping process, is a key microstructural feature that influences impact toughness of press hardening steel. In this paper, a special Charpy V-notch impact test is developed to quantify the impact toughness of press hardened steel of varying prior austenite grain size by stacking a number of thin sheets via mechanical riveting. Both the ductile-to-brittle transition temperature and upper shelf energy are analyzed in an effort to establish a correlation between impact toughness and prior austenite grain size. Based on this result, impact performance variation of a hot-formed component can be better understood and quantitatively characterized.
2016-04-05
Journal Article
2016-01-0356
Hua-Chu Shih
Prephosphated steel was developed by applying phosphate coating on zinc coated sheet steel to increase the lubricity in the automotive stamping process. The phosphate coating was also found can further absorb the lubricant which can reduce excess amount of lubricant dripping on the die surface and the press floor. Due to its enhanced lubricity characteristic, the applications have grown rapidly including the lately developed advanced high strength steels (AHSS). For the applications of the AHSS, due to the high strength property, it is crucial to understand their performance under more extreme forming conditions such as higher die temperature, contact pressure and sliding speed, etc. The intent of this study is to investigate the tribological performance and die wear behavior of the prephosphated AHSS under these forming conditions in the die tryout and production conditions.
2016-04-05
Journal Article
2016-01-0425
Andreas Karl, Chad Beamer
While the excellent corrosion resistance of austenitic and duplex stainless steels has resulted in wide commercial application of these materials, poor tribological behavior, especially low abrasive / adhesive wear resistance and a tendency to fretting, has prevented the use of these materials in applications where both corrosion and wear resistance are required. For more than 20 years, low temperature carburizing has offered a solution to enhance mechanical properties without altering the corrosion resistance. These thermo-chemical diffusion processes form carbon or nitrogen S-phase while avoiding carbide precipitation that causes sensitization. This paper shows some application examples of low temperature carburized austenitic stainless steels in kinematic and static parts of automobiles. Turbo chargers gain more and more popularity due to the need of down-sizing and fuel efficiency.
2016-04-05
Journal Article
2016-01-0504
Shin-Jang Sung, Jwo Pan
New analytical stress intensity factor solutions for spot welds in lap-shear specimens under clamped loading conditions are developed based on the beam bending theory to account for the bending moment on the clamped grips and the closed form solutions for rigid inclusions in thin plates under various loading conditions. The analytical solutions for selected ratios of the specimen width to the nugget diameter are compared with the computational solutions based on three-dimensional finite element analyses. Analytical stress intensity factor solutions as functions of the ratio of the specimen width to the nugget diameter for both the pinned connected and clamped loading conditions are compared and presented for future engineering applications. The analytical solutions can include the effects of the weld gap, weld bend, and load offset due to the spacer arrangement at the specimen edges.
2016-04-05
Technical Paper
2016-01-1366
Sivanandi Rajadurai, Guru Prasad Mani
Tube bends are critical in exhaust systems. The acceptability of tube bends is based on the induced level of shape imperfections considered. An analysis is presented for the performance tuning of the genetic algorithm including the importance of raw material selection, ovality and elongation property. This study is an attempt to analyze the ovality effect of STAC 60/60 material. CAE tools are essential to exploit the design of experiments and find out the optimum values of the design parameters in comparison with full factorial designs. Especially, the effects of materials, dimensions and geometry shape of the ultimate strength were discussed by both CAE and experiments. The ultimate strength of steel tube was evaluated at least 20-30% as a local strain independent of the materials. The dependency of ultimate bending angle on original centre angle of the tube bend was clarified.
2016-03-21 ...
  • March 21-22, 2016 (8:30 a.m. - 4:30 p.m.) - Troy, Michigan
  • October 24-25, 2016 (8:30 a.m. - 4:30 p.m.) - Troy, Michigan
Training / Education Classroom Seminars
Advanced High Strength Steels (AHSS) are now commonly used in automotive body structural applications. The high strength of this grade classification is attractive to help reduce mass in the automotive body through reduction in thickness. Strength also supports improvements in safety requirements so that mass increases are minimized. In some specific grades of AHSS, energy absorption is possible in addition to the high strength. This course will review the definition and properties of AHSS and cover several common applications in automotive body structures.
2016-02-04
Standard
AMS2369C
This specification covers quality assurance sampling procedures which may be used to determine conformance to applicable specification requirements of carbon and low-alloy steel castings.
2016-02-04
WIP Standard
AMS5080K
This specification covers a carbon steel in the form of bars, forgings, mechanical tubing, and forging stock.
2016-02-04
WIP Standard
AMS5069G
This specification covers a low-carbon steel in the form of bars, forgings, mechanical tubing, and forging stock.
2016-02-02
Standard
AMS5641H
This specification covers a free machining, corrosion resistant steel in the form of bars, wire, forgings, and forging stock.
2016-02-02
Standard
AMS5640V
This specification covers three types of a free-machining, corrosion-resistant steel in the form of bars, wire, forgings, and forging stock.
2016-01-22
WIP Standard
AMS5718E
This specification covers a corrosion resistant steel in the form of bars, wire, forgings, mechanical tubing, extrusions, flash welded rings, and stock for forging or flash welded rings.
Viewing 1 to 30 of 6921

Filter

  • Range:
    to:
  • Year: