Effect of Tempered Martensite Volume Fraction on Final Properties of Cold Rolled and Tempered Al TRIP Steel

2006 ◽  
Author(s):  
J. Vikram ◽  
A. M. Elwazri ◽  
S. Yue ◽  
E. Essadiqi
2010 ◽  
Vol 146-147 ◽  
pp. 678-681
Author(s):  
Zheng You Tang ◽  
Hua Ding

The effect of the partial substitution of Si by Al on the microstructures and the mechanical properties of cold rolled C-Mn-Si TRIP steel was investigated. The results show that the partial substitution of Si by Al could refine the microstructures, increase the volume fraction of ferrite and retained austenite. In addition, the excellent mechanical properties of the Al partial substituted TRIP steel could be obtained, the tensile strength, total elongation and strength-ductility of C-Mn-Si-Al TRIP steel are 739MPa, 38% and 28082MPa%, respectively.


2012 ◽  
Vol 602-604 ◽  
pp. 472-477 ◽  
Author(s):  
Li Hui Wang ◽  
Di Tang ◽  
Hai Tao Jiang ◽  
Ji Bin Liu ◽  
Yu Chen

Effects of continuous annealing process on microstructure and properties of Si based cold-rolled TRIP Steel were studied. The results show that the TRIP effect is more obvious on the condition of 800°C with 120s annealing process and 400°C with 520s aging treatment than others progress. The yield strength of the tested steel is 405MPa, tensile strength is 670MPa, elongation is 32% and strain hardening exponent is 0.230. The microstructures are ferrite, bainite and retained austenite and the volume fraction of retained austenite for the tested steel is 9.20%.


2021 ◽  
Author(s):  
Gamri Hamza ◽  
Allaoui Omar ◽  
Zidelmel Sami

Abstract The effect of the morphology and the martensite volume fraction on the microhardness, the tensile, the friction and the wear behavior of API X52 dual phase (DP) steel has been investigated. Three different heat treatments were used to develop dual phase steel with different morphologies and with different amounts of martensite: Intermediate Quenching Treatment/Water (IQ); Step Quenching Treatment (SQ) and direct quenching (DQ). Tribological tests are conducted on DP steels using a ball-on-disc configuration under normal load of 5 N and at a sliding speed of 4 cm/s were used to study the friction and wear behavior of treated samples. Results show that the ferrite–martensite morphology has a great influence on the mechanical properties of dual phase steel. The steel subjected to (IQ) treatment attain superior mechanical properties compared to the SQ and the DQ treatments. On the other hand, it is also found that the friction coefficient and the wear rate (volume loss) decrease when the hardness and the martensite volume fraction increase. The steel with fine fibrous martensite provide good wear resistance.


Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5975
Author(s):  
Jae-Hwan Kim ◽  
Jong-Min Jung ◽  
Hyunbo Shim

The tensile properties and damping capacity of cold-rolled Fe–20Mn–12Cr–3Ni–3Si alloys were investigated. The martensitic transformation was identified, including surface relief with a specific orientation and partial intersection. Besides, as the cold rolling degree increased, the volume fraction of ε-martensite increased, whereas α’-martensite started to form at the cold rolling degree of 15% and slightly increased to 6% at the maximum cold rolling degree. This difference may be caused by high austenite stability by adding alloying elements (Mn and Ni). As the cold rolling degree increased, the tensile strength linearly increased, and the elongation decreased due to the fractional increment in the volume of martensite. However, the damping capacity increased until a 30% cold rolling degree was approached, and then decreased. The irregular tendency of the damping capacity was confirmed, depicting that it increased to a specific degree and then decreased as the tensile strength and elongation increased. Concerning the relationship between the tensile properties and the damping capacity, the damping capacity increased and culminated, and then decreased as the tensile properties and elongation increased. The damping capacity in the high-strength area tended to decrease because it is difficult to dissipate vibration energy into thermal energy in alloys with high strength. In the low-strength area, on the other hand, the damping capacity increased as the strength increased since the increased volume fraction of ε-martensite is attributed to the increase in the damping source.


2016 ◽  
Vol 879 ◽  
pp. 1651-1655 ◽  
Author(s):  
Leandro Paulo de Almeida Reis Tanure ◽  
Cláudio Moreira de Alcântara ◽  
Tarcísio Reis de Oliveira ◽  
Dagoberto Brandão Santos ◽  
Berenice Mendonça Gonzalez

The use of Ferritic Stainless Steels has become indispensable due its lower cost and the possibility to replace austenitic stainless steels in many applications. In this study, cold rolled sheets of two stabilized ferritic stainless steels with 85% thickness reduction were annealed by applying a heating rate of 24 oC/s and a soaking time of 24 s. The niobium stabilized ferritic stainless steel type ASTM 430 (430Nb) was annealed at 880 oC while the niobium and titanium bi-stabilized steel ASTM 439 was annealed at 925 oC. The annealed samples were tensile tested and due to the smaller grain size, steel 430Nb, showed a higher yield stress and a higher total elongation. Concerning drawability the steel ASTM 439 presented a better performance with higher average R-value, lower planar anisotropy coefficient and a greater value for Limit Drawing Ratio (LDR). These results are explained in terms of the differences in size and volume fraction of precipitates between the two steels.


2012 ◽  
Vol 706-709 ◽  
pp. 2181-2186 ◽  
Author(s):  
Tulio M.F. Melo ◽  
Érica Ribeiro ◽  
Lorena Dutra ◽  
Dagoberto Brandão Santos

The increasing demand, mainly from the automobile industry, for materials which combine high strength, high ductility and low specific weight makes steels with the TWIP (TWinning Induced Plasticity) effect a promising material to meet these requirements. This work aimed to study the kinetics of isothermal recrystallization of a TWIP steel (C-0.06%, Mn-25%, Al-3%, Si-2%, and Ni-1%) after cold rolling. The steel was hot and cold-rolled and then annealed at 700°C with soaking times ranging from 10 to 7200 s. Microstructural analysis was performed using light (LM) and scanning electron microscopy (SEM). Furthermore, quantitative metallography was performed in order to evaluate the recrystallized volume fraction and grain size. A JMAK based model was applied to describe the nucleation grain growth process. The restoration of the steel was also evaluated by microhardness tests. A complete recrystallization after 7200 s at 700°C was observed. It was found that with increasing annealing times, the recrystallized volume fraction also increases, while the nucleation and growth rates decrease, in agreement with the results for plain carbon steels.


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