激光熔覆Fe基合金涂层的高温磨损性能

High-Temperature Wear Performance of Laser Cladding Fe-Based Alloy Coating

为了提高H13钢的高温耐磨性,通过激光熔覆在H13钢表面成功制备了Fe基合金涂层,对涂层和H13钢进行了高温磨损测试,对涂层和H13钢的高温磨损性能进行了比较研究,并讨论了其磨损机理。结果表明:与H13钢相比,该涂层的磨损率均比H13低,具有更好的高温耐磨性,尤其是在600℃时表现更为突出。在400℃下50~150 N时,涂层的磨损率随载荷增加而逐渐增加,而H13基体则是先增后降,但涂层的磨损率均比基体低。在600℃下50~100 N时,H13钢的磨损率随载荷增加而增加,在载荷为150 N时,H13钢的磨损率开始急剧增加,发生了严重的塑性挤出磨损,此条件下,涂层的磨损率也随着载荷的增加而增加,在150 N时增速较大,但磨损率远小于基体。在400℃下50~150 N时和600℃下50~100 N时涂层普遍存在氧化性轻度磨损,由此产生的致密的摩擦层可为涂层提供良好的保护。当温度和载荷分别达到600℃和150 N时,涂层疏松的摩擦层逐渐失去其保护功能,且普遍存在氧化磨损。

In order to improve the high temperature wear resistance of H13 steel,a Fe-based alloy coating was successfully prepared on the surface of H13 steel by laser cladding.High temperature wear tests were carried out for the coating and H13 steel.The high-temperature wear performance of the coating and H13 steel was comparatively studied,and the wear mechanisms were also discussed.Results showed that compared to H13 steel,the wear rate of the coating was lower than that of H13 steel,and it had better high temperature wear resistance,especially at 600℃.When sliding under 50~150 N at 400℃,with an increase of load,the wear rate of the coating slightly increased while the wear rate of the H13 matrix increased first and then decreased,but the wear rate of the coating was lower than that of the matrix.When sliding under 50~100 N at 600℃,the wear rate of H13 steel increased with the increase of load.As the sliding conditions reached 150 N,the wear rate of H13 steel started to increase rapidly and severe plastic extrusion wear occurred.Under this condition,the wear rate of the coating also increased with the increase of the load,and the growth rate was larger at 150 N,but the wear rate was much smaller than that of the substrate.Under 50~150 N at 400℃and 50~100 N at 600℃,the coatings generally had mild oxidative abrasion,by which a dense friction-layer was found to provide a good protection for the coating.As the temperature and load reached 600℃and 150 N,respectively,loose friction-layer of coating gradually lost its protective function and oxidative wear was common.