用Gleeble-3500热力模拟试验机对铸态M2高速钢进行1000~1150℃及0.01~1.0 s-1的热压缩变形,获得了铸态M2高速钢的流变曲线,分析了变形后的显微组织特性。结果表明,铸态M2高速钢的流变应力和峰值应变均随变形温度的降低和应变速率的提高而增大,其热变形激活能为550.16 kJ/mol,同时得到了其热变形方程,建议其在1050~1150℃和0.01~1.0 s-1的工艺条件下进行热加工。
1 M2 U1 单项选择 1. It is reported that the police will soon ________ the case of two missing children. A. look upon B. look after C. look into D. look out [解析 ] C 考查动词短语辨析。根据题意可知应选 look into “调查”。 2. I am ________ that Peter is guiltless unless you can show me ________ evidence. A.convincing; convincing B.convinced; convinced C.convinced; convincing D.convincing; convinced [解析 ] C 考查现在分词和过去分