35CrMo钢硫氮共渗层的摩擦学性能

Friction Property of Sulfurizing-Nitriding Layer on 35CrMo Steel

目前,低温离子渗硫技术在石油钻杆丝扣上的应用还没有先例。应用离子渗氮与离子渗硫技术,在35CrMo钢表面制备了硫氮共渗复合层。采用自制的球-盘磨损试验机,在含铜润滑脂润滑条件下,对比研究了离子渗氮层与硫氮共渗层的摩擦磨损性能;采用白光干涉仪和扫描电子显微镜观察了表面改性层和磨损表面的形貌,利用纳米压痕仪测量了渗层的硬度和弹性模量,用X射线光电子能谱研究了磨损表面边界润滑膜的元素成分及其含量随深度的变化。结果表明,35CrMo钢经硫氮共渗处理后,表面比较粗糙,硬度较低,符合理想的摩擦表面要求;硫氮共渗层有了渗氮层的支撑,其减摩耐磨性能在低速低载下优于渗氮层,满足钻杆接头的使用性能要求。

Nitriding layer and sulfurizing-nitriding composite layer were prepared on the surface of 35CrMo steel by using ion nitriding and sulfurizing technology.The friction and wear behavior of the nitriding layer and sulfuriz-ing-nitriding composite layer under the lubrication of grease con-taining Cu was comparatively evaluated using a ball-on-disk wear tester.The original and worn surface morphologies of the nitriding layer and sulfurizing-nitriding composite layer were observed using an optical profiler and a scanning electron microscope.The hardness and elastic modulus of the surface-modifying layer were measured using a nanoindentation device.Moreover,the elemen-tal composition and concentration variation with depth at the boundary of the worn surface were analyzed by means of X-ray photoelectron spectroscopy.Results show that sulfurizing-nitri-ding composite layer is rougher and has a lower hardness.Under low sliding rates and loads,the sulfurizing-nitriding composite layer was superior to the nitriding layer in properties of friction and wear,meeting the requirement for performance of drilling rod joints.