再论55SiMnMo钢贝氏体形态  

Further Discussion on the Bainite Morphology of 55SiMnMo Steel

作　　者：刘正义[1] 林鼎文[2] 

机构地区：[1]华南理工大学机械与汽车工程学院,广东广州510640 [2]华侨大学机电及自动化学院,福建厦门361021

出　　处：《华侨大学学报（自然科学版）》2014年第6期616-619,共4页Journal of Huaqiao University(Natural Science)

摘　　要：讨论55SiMnMo钎钢在正火(连续空冷)和等温条件下所转变的贝氏体,分析这两种贝氏体的形貌和形态差异.研究结果表明:55SiMnMo钢加热(超过AC3点)奥氏体化后,正火(连续空冷)获得的金相组织是B4型无碳化物上贝氏体(铁素体+富碳奥氏体);在等温条件下:等温的温度达到或超过400℃,长时间等温的金相组织是B2型,B4型混合贝氏体,B2型的比例多过B4型(以B2型为主),短时间的等温则是以B4型为主;等温的温度低过400℃,即使长时间等温,其金相组织仍是B4型贝氏体.This paper discusses bainite of 55SiMnMo rock-drill steel,transformed under normalization （continuous cool-ing）and isothermal condition by analyzing the topography and morphology disparity of the two types of bainite.The research results demonstrate that the metallographic structure,gotten by normalization （continuous cooling）,is B4 type no-carbide-bainite （ferrite and carbon-rich austenite）after heating （over AC3 point）and austenitizing 55SiMnMo steel. Under isothermy condition,the metallographic structure,gotten by long-time isothermy,is B2 type and B4 type mixed bainite with the temperature of or over 400 ℃.The proportion of B2 type is higher than B4 type （mainly B2 type）.And B4 type is mainly gotten with the short isothermy time.While the isothermy is below 400 ℃,the metallographic structure is still B2 type bainite even though the isothermal time is long.

关 键 词：55SiMnMo钢 贝氏体 正火 等温 

分 类 号：TG151.1[金属学及工艺—热处理]