横拉机H13钢耐磨导轨激光表面淬火+渗氮复合处理

Laser surface quenching and nitriding composite treatment of H13 steel wear⁃resistant guide rail for TDO

为提高横拉机H13钢耐磨导轨的使用寿命,对导轨(心部硬度约300 HV0.3)分别用激光表面淬火、气体渗氮、激光表面淬火+气体渗氮进行表面强化处理,以表面硬度、硬化层深度、硬度梯度为依据进行耐磨性的对比分析。结果表明,气体渗氮表面硬度高(>980 HV0.3),但硬化层深度较浅(仅能达到约0.27 mm);激光表面淬火成倍增加硬化层深度(可达约0.7 mm),但表面硬度不及气体渗氮(最高仅达到764 HV0.3);先激光表面淬火(P=2500 W,v=4 mm/s)后气体渗氮(540℃×25 h)复合处理则能兼有两种工艺的优点,获得更高的表面硬度(>980 HV0.3)和硬化层深度(可达0.61~0.67 mm),能有效提高导轨的耐磨性。

In order to improve the service life of H13 steel wear⁃resistant guide rail of the TDO,the guide rail with a core hardness of about 300 HV0.3 was treated by laser surface quenching,gas nitriding,laser surface quenching+gas nitriding composite treatment process respectively for surface strengthening,and then the wear resistance was compared and analyzed based on surface hardness,hardening layer depth and hardness gradient.The results show that the gas nitriding can significantly improve the surface hardness(>980 HV0.3),but the depth of the hardened layer is shallow(only about 0.27 mm).The laser surface quenching increases the depth of the hardened layer by several times(up to about 0.7 mm),but the surface hardness is lower than that after the gas nitriding(up to 764 HV0.3).By the laser surface quenching(P=2500 W,v=4 mm/s)followed by gas nitriding(at 540℃for 25 h)composite treatment,the advantages of both the processes can be combined to achieve higher surface hardness(>980 HV0.3)and increase the hardening layer depth(up to 0.61⁃0.67 mm),and effectively improve the wear resistance of the guide rail.