低、中碳合金钢中的马氏体与贝氏体形态

MORPHOLOGY OF MARTENSITE AND BAINITE IN LOW AND MEDIUM CARBON ALLOY STEELS

低、中碳合金钢中的马氏体除局部区域因成分偏析呈孪晶亚结构外,主要是位错亚结构的板条马氏体。低碳合金钢的中温转变组织主要有兰类,即粒状组织、上贝氏体和下贝氏体。其中上贝氏体又分为粒状贝氏体、准上贝氏体和典型上贝氏体;下贝氏体又有准下贝氏体、变态下贝氏体和典型下贝氏体。中碳合金钢的中温转变组织只有上、下贝氏体。其中上贝氏体又分为准上贝氏体和典型上贝氏体,而下贝氏体则包括准下贝氏体、变态下贝氏和典型下贝氏体。

The martensite in low and medium carbon alloy steels mainly is lath martensite of dislocation substructure besides little twin substructure at the segregation regions of chemical composition. Three types microstructures are formed at intermedium temperature in the low carbon alloy steels, that is granular structure, upper and lower bainite. The upper bainite includes granular bainite, upper meta-bainite and typical upper bainite, the lower bainite includes lower meta-bainite, abnormal bainite, and typical bai nite. The intermedium temperature microstructure of medium carbon alloy steel is upper and lower bainite. The upper bainite includes upper meta-bainite and typical upper bainitd, the lower bainite includes lower meta-bainite, abnormal lower bainite, and typical lower bainite.