固体渗碳工艺对SAE8620H钢奥氏体晶粒度评定的影响  

Effect of Pack Carburizing Process on Evaluation of Austenite Grain Size of SAE8620H Steel

作　　者：廖振成 代孟强 黄道龙 候清宇 黄贞益 LIAO Zhencheng;DAI Mengqiang;HUANG Daolong;HOU Qingyu;HUANG Zhenyi(School of Metallurgical Engineering,Anhui University of Technology,Ma’anshan 243000,Anhui China)

机构地区：[1]安徽工业大学冶金工程学院,安徽马鞍山243000

出　　处：《热处理》2021年第3期12-15,20,共5页Heat Treatment

摘　　要：低碳钢的奥氏体晶粒度可通过渗碳来评定。采用不同工艺对含0.198%C的SAE8620H钢进行了固体渗碳,研究了加热工艺和渗碳剂成分对钢的奥氏体晶粒评定的影响。结果表明:与采用全新渗碳剂渗碳的SAE8620H钢试样相比,采用新、旧渗碳剂比例为4∶6的混合渗碳剂渗碳的试样表面不易形成粗大或网状碳化物,易于显示奥氏体晶粒;与缓慢加热至渗碳温度的试样相比,高温进炉渗碳的试样的奥氏体晶粒较均匀细小,且不易形成混晶组织,有助于准确测定低碳钢在实际渗碳过程中的奥氏体晶粒度。Size of austenite grains in low-carbon steels is likely to be evaluated with the aid of carburizing.SAE8620H steel with 0.198%C was pack carburized by using different procedures,and the effect of heating practices and compositions of carburizing medium on the evaluation of austenite grain size was investigated.The results indicated that(a)the SAE8620H steel specimen pack carburized in a mixed medium consisting of 4 parts of fresh carburizing medium and 6 parts of used carburizing medium was less easy to form massive or net carbide at surface than did the specimen pack carburized in freshly made-up craburizing medium,and,as a result,the austenite grains were easy to appear;and(b)compared with the specimen heated slowly to carburizing temperature,the specimen loaded in the furnace at high temperature and carburized exhibited more uniform and finer grains,and was less prone to formation of a mixed grain structure,which helps to accurately measure austenite grain size of low-carbon steels in the actual carburizing.

关 键 词：低碳钢 固体渗碳 显微组织 奥氏体 晶粒度 

分 类 号：TG156.1[金属学及工艺—热处理]