成分及冷却工艺对复相钢、马氏体钢组织与性能的影响

在实验室用真空感应炉冶炼复相钢和马氏体钢,锻坯、控轧成3 mm厚的板材后采用不同冷却模式进行控制冷却.研究了成分、冷却工艺对组织与力学性能的影响.结果表明:卷取温度降低,钢的强度上升,伸长率下降,组织由铁素体 珠光体向贝氏体、马氏体转变;低温卷取时钢的强度主要取决于碳含量,硅含量的提高使钢的强度和塑性均有所提高;分段冷却对组织与性能的影响较复杂.通过不同的控制冷却工艺实现了用相同的成分获得不同强度等级要求的汽车用先进高强度钢.

Effect of Chemical Composition and Cooling Process on Microstructure and Mechanical Properties of Multiphase Steel and Martensite Steel

The effect of chemical composition and cooling process on microstructure and mechanical properties of specimens taken from the controlled rolled and cooled strips of vacuum melted multiphase and martensite steels were researched. The results show that the microstructure changes from ferrite plus pearlite to bainite and martensite, the strength increases and the elongation decreases with the decreasing of coiling temperature. The strength of sheet coiled at low temperature is mainly decided by the content of carbon, while both strength and elongation are improved with the increase of silicon content. The effect of two-step cooling process on microstructure and mechanical properties is complex. The advanced high strength automobile steel of same chemical composition can be manufactured by different controlled cooling processes for different strength classes.