低Si和高Al冷轧TRIP钢的组织和性能分析

Analysis on microstructure and properties of low Si and high Al cold rolled TRIP steel

改变传统TRIP钢的Si或Al含量,结果表明,w(Si)为0.61%的试验钢与传统的TRIP钢力学性能相当;w(Al)为1.20%的试验钢抗拉强度略偏低,但其n值较高,达0.235。2种试验钢的组织均为铁素体+小岛状马氏体。低Si或以Al代Si并通过适当的生产工艺,可以产生TRIP效应,低Si的试验钢残余奥氏体体积分数达6.20%,高Al的试验钢残余奥氏体体积分数达5.11%。扫描电镜观察断口形貌表明,2种试验钢拉伸试样断口均呈韧窝状,并且可避免高Si含量对钢板表面的不利影响。

The experiment on the change of Si or Al contents of the traditional TRIP steel has been carried out. Results show that the properties of the trial steel with 0.61% Si are almost as equal as that of the traditional TRIP steel, and the tensile strength of the trial steel with 1.20 % Al is appreciably descending. But the value of the trial steel with 1.20% Al is very good,up to 0.235. The microstructures of two specific steels are ferrite and small island structure martensite. The effect of TRIP with low Si or Al instead of Si can be produced under the appropriate production process. The residual austenite content of the trial steel with low Si is 6.20% and that of the trial steel with high Al is 5.11%. The fracture analysis by SEM proves that the fractures of tensile samples for two trial steels appear dimple shape and the disadvantageous influence is avoided on the high Si content to the surface of steel sheet.