中文摘要：

利用Gleeble-3180热模拟机对铸态12%wtCr马氏体不锈钢进行了高温热压缩实验,研究了该钢在900～1200℃和0.001～10s^-1条件下的热变形行为,建立了热加工图。分析了工艺参数对铸态12%Cr钢微观组织的影响。结果表明铸态12%Cr钢的流变应力随变形温度的提高和应变速率的降低而增大。动态再结晶晶粒尺寸与Z参数成反比关系。依据动态材料模型,建立了热加工图,流变失稳区集中在900～1050℃、应变速率大于1s^-1的区域,其微观组织表现为变形带和M/啄相界处的微孔、微裂纹。最佳的热加工工艺参数范围为1050～1200℃和0.001～0.01s^-1,在稳定变形区,粗大的毫米级的柱状晶会被细化到10～40μm。

英文摘要：

The as-cast 12wt% Cr martensitic stainless steel in high temperature was compressed by using Gleeble-3180 hot simulator. Its hot deformation behavior was studied under condition 900-1200℃ and the strain rate range of 0.001-10 sl. A hot processing map was established. The influence of process parameters on the microstructure of as-cast 12%Cr steel was analyzed. The results show that the flow stress of as-cast 12%Cr steel increases with increasing deformation temperature and decreasing strain rate. Dynamic recrystallization （DRX） grain size has an adverse relation with Zener-Hollomon parameter. The hot processing map was established according to dynamic material model. The flow instability region concentrats in region of 900-1050℃ and strain rate 〉10 s^-1, and the microstructure is the micropores and microcracks in deformation bands and M/δ phase boundary. Optimal hot processing parameters are the deformation temperatures of 1050-1200℃ and strain rate of 0.001-0.01 s^-1. Bulky millimeter columnar crystals will be refined to 10-40 μm in the steady deformation region.