大型铸锻件粗晶及其解决方法的探讨  

Research on Coarse Grain of Heavy Castings and Forgings and Its Solution

作　　者：申鹏[1] 周勇[1] 

机构地区：[1]振石集团东方特钢股份有限公司技术中心,浙江314005

出　　处：《大型铸锻件》2009年第3期14-17,共4页Heavy Casting and Forging

摘　　要：针对大型铸锻件粗晶问题,分析了其产生的本质原因。通过对实际例子的分析,给出了应对的热处理工艺。分析表明,产生粗晶的实质原因是过热组织。契尔诺夫b点随着加热速率和钢种的变化而变化。消除粗晶有两种方法,一是加热到契尔诺夫b点以上温度,二是通过两次正火或退火产生的内因加工硬化破坏粗晶组织的遗传。为了提高生产率,一般使用加热到契尔诺夫b点以上温度来消除粗晶,而对于锻件或铸件重量很大的工件,一般采用两次正火或退火来消除粗晶。For the coarse grain problem of heavy castings and forgings, the essential reasons have been analyzed. By analyzing the practical example, the relative heat treatment process has been presented. The analyzed results indicate that the reason for appearance of coarse grain is the overheated structure. The Qiemuofu point b would change in company with the heating speed and the difference of steel grades. There are two methods to eliminate coarse grain： first, heating to the temperature above Qiemuofu point b; second, destroying organization heredity of coarse grain by the work hardening of internal cause with twice normalizing or annealing. In order to improve productivity, the first method of heating to the temperature above Qiemuofu point b would be used normally. For the heavy casting and forging workpieces, the second method of twice normalizing or annealing would be used for eliminate the coarse grain.

关 键 词：锻件 契尔诺夫b点 正火 粗晶 热处理 

分 类 号：TG142[一般工业技术—材料科学与工程]