【摘要】 TRIP钢在两相区760℃退火,在贝氏体区400℃等温处理。根据GB15825.8—1995对试样进行FLD试验,并利用扫描电镜进行断裂机理分析。试验表明,该TRIP钢的FLD0可达27.2%,具有良好的成形性;应变时等轴状铁素体(F)先被拉伸变形,在F晶粒中及其边界产生微孔洞,孔洞聚集长大形成裂纹,裂纹碰到硬质相贝氏体(B)时沿其边缘扩展,遇到残余奥氏体(RA)时,发生TRIP效应释放应力导致裂纹转向。更多还原

【Abstract】 In this paper -when the temperature at bainite area is 400 ℃,with the temperature 760 ℃ at α+γ area - it was studied the forming-limit diagram(FLD) and fracture mechanism of TRIP steel .Experiment showed that the FLD0 of the TRIP-assisted steels is 27.2%,which indicates it has fine formability.When formed,equiaxed grain ferrite(F)begins first tensile strain. In the middle of F grain and it’s edge - minute hole creates,gathers and grows into crack.When crack meets the hard phase -bainite -it expands along the edge of the bainite .When crack falls on the retained austenite- concentrating stress make retained austenite phase change into martensite which is TRIP effect -and then crack modify the direction.更多还原