Si-Mn系TRIP钢板的组织性能稳定性

Stability of microstructure and mechanical properties of Si-Mn TRIP steels

以冷轧600、800 MPa级TRIP钢板为研究对象,通过对比自然时效前后母材的显微组织、显微硬度、电阻点焊的最佳工艺参数以及回火温度对钢板硬度的影响,研究了Si-Mn系TRIP钢板的稳定性。结果表明,静置1年后600、800 MPa级TRIP钢板的显微硬度分别从193、253 HV0.1提高到228、297 HV0.1;点焊工艺参数变小,回火温度对硬度的影响不明显。产生这些性能变化的原因是钢板中部分奥氏体在自然时效中发生马氏体相变。且600 MPa级TRIP钢板与800 MPa级相比,前者的稳定性较高。

Based on cold-rolled 600 MPa and 800 MPa grade TRIP steels,the stability of microstructure and mechanical properties of Si-Mn TRIP steels was investigated by comparison of variety of the microstructure,microhardness and optimum resistance spot welding parameters before and after nature aging and the effect of tempering temperature on the hardness.The results show that 1 year nature aged,the microhardness of 600 MPa and 800 MPa grade TRIP steels is increased from 193 HV0.1 and 253 HV0.1 to 228 HV0.1 and 297 HV0.1,respectively,the spot welding process parameters become smaller and the effect of tempering temperature on hardness is not obvious.These property changes are due to the transformation of part austenite to martensite during nature aging and the stability of 600 MPa grade TRIP steel is higher than that of the 800 MPa grade one.