martenn.貂；貂皮martens' extensometer营舍专业训练(美国)martensitic cast iron马氏体铸铁,马氏铸铁martensitic hardening马氏体硬化martensite morphology马氏体形态martensitic transtion马丁跃迁martensite transition马氏体相变Martensite temperature马氏体温度martensitic transition马氏体相变martensite cold working马氏体冷作处理martens hardness tester马氏硬度试验器