CAJ | 학술논문

在实验室用 Gleeble3500热模拟试验机制备了一种无 Si TRIP 钢.利用拉伸试验机、扫描电镜、透射电镜、X射线衍射以及热膨胀仪对其力学性能、微观组织和相变规律进行研究,在此基础上分析了贝氏体相变温度和时间对力学性能和残余奥氏体的影响.无 Si TRIP 钢呈现出良好的整体力学性能,抗拉强度分布在740～810 MPa,延伸率均在25%以上,最高可达32%以上;贝氏体等温温度为420℃时能获得最佳的综合力学性能,抗拉强度随贝氏体相变时间增加而下降,延伸率随之上升,而屈服强度没有显著变化.无 Si TRIP 钢的铁素体晶粒大小约为3～4μm,比含 Si TRIP钢铁素体晶粒细小;残余奥氏体的体积分数在8%～10%,比含 Si TRIP 钢低约3%;420℃保温300 s 后贝氏体相变基本结束,而碳的扩散仍然在进行;无 Si TRIP 钢贝氏体相变速率比含 Si TRIP 钢快,贝氏体相变总量也更多.
재실험실용 Gleeble3500열모의시험궤제비료일충무 Si TRIP 강.이용랍신시험궤、소묘전경、투사전경、X사선연사이급열팽창의대기역학성능、미관조직화상변규률진행연구,재차기출상분석료패씨체상변온도화시간대역학성능화잔여오씨체적영향.무 Si TRIP 강정현출량호적정체역학성능,항랍강도분포재740～810 MPa,연신솔균재25%이상,최고가체32%이상;패씨체등온온도위420℃시능획득최가적종합역학성능,항랍강도수패씨체상변시간증가이하강,연신솔수지상승,이굴복강도몰유현저변화.무 Si TRIP 강적철소체정립대소약위3～4μm,비함 Si TRIP강철소체정립세소;잔여오씨체적체적분수재8%～10%,비함 Si TRIP 강저약3%;420℃보온300 s 후패씨체상변기본결속,이탄적확산잉연재진행;무 Si TRIP 강패씨체상변속솔비함 Si TRIP 강쾌,패씨체상변총량야경다.
@@@@A kind of TRIP steel without Si was heat-treated on a Gleeble3500 thermal simulation testing machine. Its mechanical properties, microstructure, and phase transformation were studied by tensile machine, scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), and thermal dilatometer. The effects of bainite transformation temperature and time on the mechanical properties and retained austenite in the Si-free TRIP steel were analyzed. It is found that the Si-free TRIP steel has excellent overall mechanical properties with the tensile strength of 740 to 810 MPa and the elongation above 25%, which can reach up to 32%. The best comprehensive mechanical properties can be achieved when the isothermal bainite transformation temperature is 420 ℃. At this temperature, the tensile strength decreases and the elongation increases with the increase of bainite transformation time, but the yield strength has no significant change. The size of ferrite grains in the Si-free TRIP steel is 3 to 4 μm, smaller than that in the Si-containing TRIP steel. The volume fraction of retained austenite is 8% to 10%, about 3% lower than that in the Si-containing TRIP steel. Bainite transitions in the Si-free TRIP steel almost complete at 420 ℃ for 300 s, but the diffusion of C still continues. Compared to the Si-containing TRIP steel, bainite transitions in the Si-free TRIP steel are much faster and the bainite transformation amount is bigger.