摘要
针对4Cr5MoSiV1热作模具钢在使用过程中经受熔融铝液及冷却液的循环冲击,在热应力作用下容易产生热疲劳失效的问题。采用可控循环气体渗氮的方法分别在回火态和热疲劳态模具钢表面制备无铁氮化合物和有化合物的渗层,进行热疲劳性能测试。结果表明:循环渗氮制备的无化合物的渗层可以有效延缓热疲劳裂纹的萌生,抗热疲劳性能优于有化合物的渗层。同时,在裂纹产生前进行二次渗氮可以补充氮原子,重置压应力并增加硬度,进一步提升热疲劳抗性。
4Cr5MoSiV1 hot work die steel is generally subjected to the cyclic thermal stress caused by molten aluminum and coolant,which results in thermal fatigue failure.The controlled cyclic gas nitriding treatment was adopted for the tempered and thermal-fatigue samples to prepare nitriding layers with and without Fe-N compounds respectively.The thermal fatigue performance test was conducted.The results of thermal fatigue tests indicate that the nitriding compound-free layer exhibits better resistance to thermal fatigue crack generation than the nitriding compound layer.The secondary nitriding before crack production can complement the nitrogen atoms,reset the compression stress and increase the hardness,which is beneficial for the promotion of thermal fatigue resistance.
作者
刘海建
韩笑
陈杰
LIU Haijian;HAN Xiao;CHEN Jie(Shanghai Spaceflight Precision Machinery Institute,Shanghai 201108,China;Shanghai Aerospace Control Technology Institude,Shanghai 201108,China)
出处
《热加工工艺》
北大核心
2024年第2期24-29,共6页
Hot Working Technology
关键词
热作模具钢
可控循环气体渗氮
铁氮化合物
热疲劳性能
hot die steel
controlled cyclic gas nitriding treatment
Fe-N compounds
thermal fatigue resistance
