The Role of Transformation-Induced Plasticity in the Development of Advanced High Strength Steels

2018 ◽  
Vol 20 (6) ◽  
pp. 1701083 ◽  
Author(s):  
Li Liu ◽  
Binbin He ◽  
Mingxin Huang
Keyword(s):  
High Strength Steels ◽  
High Strength ◽  
Transformation Induced Plasticity ◽  
Advanced High Strength Steels

Wear Resistance Research of Advanced High Strength Steels

2016 ◽  
Vol 850 ◽  
pp. 197-201
Author(s):  
Chao Zhi ◽  
Yi Fei Gong ◽  
Ai Min Zhao ◽  
Jian Guo He ◽  
Ran Ding
Keyword(s):  
Wear Resistance ◽  
Twip Steel ◽  
High Strength Steels ◽  
High Strength ◽  
Wear Performance ◽  
Dp Steel ◽  
Advanced High Strength Steels ◽  
Wear Mode ◽  
Surface Phase Transformation

The wear performance and wear mechanism under two-body abrasion of five advanced high strength steels, i.e. Nanobainite (NB) steel, Tempered Martensitic (TM) steel, Dual Phase (DP) steel, Transformation Induced Plasticity (TRIP) Steel and Twining Induced Plasticity (TWIP) steel were studied. By using the scanning electron microscopy (SEM), we investigated the wearing surface. Phase transformation strengthening behavior was also be discussed by analyzing the surface and sub-surface after abrasion. The results showed that micro-cutting was the major role of wear mode in the condition of two-body abrasion. In the circumstance of two-body abrasion, hardness was an important factor, the property of wear resistance enhanced while the hardness increased except for TM steel. NB steel possessed the best wear resistance which was 1.71 times higher than that of TWIP steel. The retained austenite transformed into martensite which can improve the hardness so that it enhanced the wear resistance of NB steel.

Critical Assessment of Bainite Models for Advanced High Strength Steels

2011 ◽  
Vol 172-174 ◽  
pp. 1183-1188 ◽  
Author(s):  
Fateh Fazeli ◽  
Tao Jia ◽  
Matthias Militzer
Keyword(s):  
Bainitic Ferrite ◽  
High Strength Steels ◽  
High Strength ◽  
Transformation Model ◽  
Complex Phase ◽  
Simultaneous Formation ◽  
Transformation Induced Plasticity ◽  
Advanced High Strength Steels ◽  
Formation Kinetics ◽  
Robust Processing

Bainite is an essential constituent in the microstructure of many advanced high strength steels, e.g. ferrite-bainite dual-phase, transformation induced-plasticity (TRIP) and complex phase (CP) steels. A complex thermo-mechanical processing is employed in industry such that following ferrite formation a desired fraction of bainite can be obtained during austenite decomposition. In order to evaluate robust processing routes it would be very useful to have a bainite transformation model with predictive capabilities. In this work a transformation start criterion for bainite is proposed by defining a critical driving pressure concept. Subsequent bainite formation kinetics from a mixture of ferrite-austenite is described using phenomenological modelling methodologies. In particular, the predictive capabilities of two approaches will be critically discussed, i.e. (i) the Johnson-Mehl-Avrami-Kolmogorov (JMAK) model in conjunction with Rios treatment of the additivity rule and (ii) a nucleation-growth based model that describes simultaneous formation of bainitic ferrite and carbides. Using experimental transformation data for TRIP and CP steels, status and limitations of these models will be delineated.

The Draw-Bend Fracture Test and Its Application to Dual-Phase and Transformation Induced Plasticity Steels

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
Ji Hyun Sung ◽  
Ji Hoon Kim ◽  
R. H. Wagoner
Keyword(s):  
Shear Fracture ◽  
High Strength Steels ◽  
High Strength ◽  
High Energy ◽  
Tensile Failure ◽  
Dual Phase ◽  
Transformation Induced Plasticity ◽  
Advanced High Strength Steels ◽  
Energy Product ◽  
Dp Steels

Unpredicted sheet forming failures of dual-phase (DP) steels can occur in regions of high curvature and with little apparent necking. Such failures are often referred to as “shear fractures”. In order to reproduce such fractures in a laboratory setting, and to understand their origin and the inability to predict them, a novel draw-bend formability (DBF) test was devised using dual displacement rate control. DP steels from several suppliers, with tensile strengths ranging from 590 to 980 MPa, were tested over a range of rates and bend ratios (R/t) along with a TRIP (transformation induced plasticity) steel for comparison. The new test reliably reproduced three kinds of failures identified as types 1, 2, and 3, corresponding to tensile failure, transitional failure, and shear fracture, respectively. The type of failure depends on R/t and strain rate, and presumably on the initial specimen width, which was constant in this study. Two critical factors influencing the lack of accurate failure prediction were identified. The dominant one is deformation-induced heating, which is particularly significant for advanced high strength steels because of their high energy product. Temperature rises of up to 100 deg. C were observed. This factor reduces formability at higher strain rates, and promotes a transition from types 1 to 3. The second factor is related to microstructural features. It was significant in only one material in one test direction (of 11 tested) and only for this case was the local fracture strain different from that in a tensile failure. Alternate measures for assessing draw-bend formability were introduced and compared. They can be used to rank the formability of competing materials and to detect processing problems that lead to unsuitable microstructures.

scholarly journals The role of the microstructure on the influence of hydrogen on some advanced high-strength steels

2018 ◽  
Vol 715 ◽  
pp. 370-378 ◽  
Author(s):  
Qinglong Liu ◽  
Qingjun Zhou ◽  
Jeffrey Venezuela ◽  
Mingxing Zhang ◽  
Andrej Atrens
Keyword(s):  
High Strength Steels ◽  
High Strength ◽  
Advanced High Strength Steels

Aspects of Thermomechanical Processing of 3rd Generation Advanced High Strength Steels

2014 ◽  
Vol 783-786 ◽  
pp. 3-8 ◽  
Author(s):  
Evgueni I. Poliak ◽  
Debanshu Bhattacharya
Keyword(s):  
Thermomechanical Processing ◽  
High Strength Steels ◽  
High Strength ◽  
Continuous Annealing ◽  
Hot Strip Rolling ◽  
Strip Rolling ◽  
Advanced High Strength Steels ◽  
Hot Strip ◽  
High Elongation

The production of advanced high strength steels (AHSS) has been rapidly expanding in recent years as these steels allow for considerable reduction in weight and enhancement of car safety due to the unique combination of high strength, toughness and formability. Driven by growing demand for sheet AHSS products from carmakers, steel producers are currently developing AHSS of the so called 3rdGeneration to further facilitate weight reduction of critical safety parts while ensuring crash worthiness and high absorbed energy. Such steels not only possess tensile strength above 1000 MPa but also are being designed for exceedingly high formability: high elongation, bendability, hole expansion and strain hardening. These enhanced properties are to be achieved in final operations of continuous annealing and/or galvanizing. However, due to complicated alloy designs of 3G AHSS the role of each manufacturing stage becomes progressively significant due to its impact on the final microstructure. Therefore, hot strip rolling gains increasing importance as one of the most critical stages responsible for producing the microstructure optimal for achieving the final properties of the sheet products without impairing downstream operations. In other words, hot rolling of AHSS has to be viewed as thermomechanical processing.

Effect of Manufacturing Process on the Final Properties of Advanced High Strength Steels for Automotive Applications

2010 ◽  
Vol 638-642 ◽  
pp. 148-153 ◽  
Author(s):  
Elena V. Pereloma ◽  
Ilana B. Timokhina ◽  
Tim B. Hilditch ◽  
Peter D. Hodgson
Keyword(s):  
Automotive Industry ◽  
Manufacturing Process ◽  
Cold Working ◽  
High Strength Steels ◽  
High Strength ◽  
Product Performance ◽  
Transformation Induced Plasticity ◽  
Trip Steels ◽  
Advanced High Strength Steels ◽  
Multiphase Steels

The performance of multiphase steels with high strength and improved toughness or ductility, such as intercritically annealed dual-phase (DP) and transformation-induced plasticity (TRIP) steels, is of key importance to the automotive industry. In this work we have considered the entire manufacturing process and the effects of this on the final product performance. These steels are formed to produce the required final shape and then the car is paint baked. In this work we also consider the effect of cold working and bake hardening on the fatigue life of the components.

A review of the influence of hydrogen on the mechanical properties of DP, TRIP, and TWIP advanced high-strength steels for auto construction

2016 ◽  
Vol 34 (3) ◽  
pp. 127-152 ◽  
Author(s):  
Qinglong Liu ◽  
Qingjun Zhou ◽  
Jeffrey Venezuela ◽  
Mingxing Zhang ◽  
Jianqiu Wang ◽  
...  
Keyword(s):  
High Strength Steels ◽  
High Strength ◽  
Significant Loss ◽  
Transformation Induced Plasticity ◽  
Trip Steels ◽  
Advanced High Strength Steels ◽  
Ductile Fractures ◽  
Twip Steels ◽  
Steel Properties ◽  
Fracture Features

AbstractThe literature is reviewed regarding the influence of hydrogen on dual-phase (DP), transformation-induced plasticity (TRIP), and twinning-induced plasticity (TWIP) steels. Hydrogen influences DP steels by decreasing ductility while strengths are largely unaffected. TRIP steels may be susceptible to hydrogen embrittlement (HE) as indicated by the loss of ductility and some brittle fracture features. The literature on the influence of hydrogen on TWIP steels was inconsistent. Some researchers found no significant influence of hydrogen on TWIP steel properties and fully ductile fractures, whereas others found a significant loss of ductility and strength due to hydrogen and some brittle features. Possible countermeasures for HE are tempering for DP and TRIP steels and aluminum alloying for TWIP steels.

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