Lesson 8 Cold Working and Hot Working 机械工程专业英语 教学课件.ppt

* * 机械工程专业英语 课文分析 The above considerations provide the basis for classification of forging temperature ranges, namely, hot working (hot forging) and cold working (cold forging). Hot working is considered to be plastic deformation that is accomplished above the recrystallization temperature. The use of the term “hot working” usually implies that the material is heated—but not always. For example, the recrystallization of lead takes place at very low temperatures. By the above definition, lead forged at room temperature is being hot worked. Lesson 8 Cold Working and Hot Working 课文分析 上述考虑因素提供了锻造温度系列的分类基础，换句话说，分热加工（热锻）和冷加工（冷锻）。 The above considerations provide the basis for classification of forging temperature ranges, namely, hot working (hot forging) and cold working (cold forging). 在再结晶温度以上才能完成塑性变形加工的就是热加工。 n.再结晶 Lesson 8 Cold Working and Hot Working 　 Hot working is considered to be plastic deformation that is accomplished above the recrystallization temperature. 课文分析 使用“热加工”这一术语通常意味着——材料一般要加热，但并不总是要加热。例如，铅的再结晶就是在很低的温度下进行。 The use of the term “hot working” usually implies that the material is heated—but not always. For example, the recrystallization of lead takes place at very low temperatures. 根据以上定义，在室温条件下铅的锻造也是热加工。 Lesson 8 Cold Working and Hot Working 　 By the above definition, lead forged at room temperature is being hot worked. 机械工程专业英语 课文分析 Cold working is defined as plastic deformation below the recrystallization temperature. Several common metals, or their alloys, have recrystallization temperatures in the order of 750oC~900oC. To improve properties, several of these alloys are strain hardened by forging in the range of 550oC~700oC. Although by definition, this is truly “cold work”, it is often referred to as “warm work”. Lesson 8 Cold Working and Hot Working 课文分析 在再结晶温度以下的塑性变形被定义为冷加工。 Cold working is defined as plastic deformation below the recrystallization temperature. 几种常用金属或他们的合金，其再结晶温度大约