齿轮钢高温渗碳后的疲劳性能  

Fatigue Properties of Gear Steels After High Temperature Carburizing

作　　者：杨延辉[1,2] 王毛球[2] 陈敬超[1] 董瀚[2] 

机构地区：[1]昆明理工大学材料学院,云南昆明650093 [2]钢铁研究总院先进钢铁材料国家工程研究中心,北京100081

出　　处：《钢铁》2013年第7期53-57,83,共6页Iron and Steel

基　　金：国家"863"计划资助项目(2006AA03Z526)

摘　　要：利用旋转弯曲疲劳试验方法,研究了Nb和Ti微合金化20CrMn齿轮钢(20CrMnNb钢:w(Nb)0.077%;20CrMnTiNb钢:w(Nb)0.048%+w(Ti)0.038%)经1 000℃高温渗碳后的疲劳性能。结果表明,Nb-Ti复合微合金化的20CrMnTiNb钢中析出相尺寸小、数量多,其渗碳层原奥氏体晶粒平均尺寸明显低于Nb微合金化的20CrMnNb钢,因而20CrMnTiNb钢的疲劳极限高于20CrMnNb钢。疲劳断口观察发现,20CrMnNb和20CrMnTiNb钢主要以近表面基体方式起裂,渗碳层中疲劳裂纹沿晶界扩展,因而晶粒尺寸较细的20CrMnTiNb钢的疲劳性能较高。The fatigue properties of microalloying gear steels with Nb and Ti（steel A1：w（Nb）0.077%;steel A2：w（Nb）0.048%＋w（Ti）0.038%） after carburized at 1 000 ℃ were investigated by means of rotating bending fatigue tests.The results show that the precipitates in steel A2 microalloyed with Nb and Ti are smaller in size and higher in volume fraction than those in steel A1 microalloyed only with Nb resulting in the higher fatigue limit for steel A2 compared with steel A1.The SEM observation of fracture surface show that the fatigue crack initiates from the near surface matrix for both steels,and it propagates around grain boundaries in the carburized case,and thus superior fatigue properties are found for steel A2 with finer and more uniform prior austenite grains in carburized case layers.

关 键 词：齿轮钢 高温渗碳 微合金化 析出相 疲劳性能 

分 类 号：TG156.81[金属学及工艺—热处理]