固溶处理对激光熔覆Stellite6合金涂层性能的影响

Effect of Solution Treatment on the Performance of Laser Cladding of Stellite6 Alloy Coating

目的通过激光熔覆的方法,在45~#钢板上沉积stellite6合金涂层,并研究涂层性能。方法通过Olympus光学显微镜对热处理前后涂层的显微组织和形貌特征进行分析;通过HV-1000B显微硬度计对涂层的力学性能进行研究。结果与未经热处理的涂层相比,经过热处理后,组织中树枝晶及胞状晶的数量明显减少,等轴晶粒增多。晶粒长大,合金元素均匀分布,横向及纵向硬度均有不同程度下降。经过固溶处理后的涂层横向与纵向显微硬度的平均值分别为HV350和HV490,未经热处理的涂层横向与纵向显微硬度的平均值分别为HV520和HV556。经热处理后,虽然涂层硬度有所降低,但组织更为均匀,塑性提高,综合性能提高。结论热处理工艺以制备涂层及后续处理的方式改变了单一依靠沉积参数提高涂层性能的方法,使激光熔覆Stellite6合金涂层的综合性能得到了提高。

The work aims to deposit stellite6 alloy coating on 45# steel sheet by virtue of laser cladding and study performance of the coating. Microstructure and morphological characteristics of the coating before and after heat treat- ment were analyzed by Olympus optical microscope, Mechanical property of the coating was studied by HV-1000B mi- crohardness tester. Compared with the coating without heat treatment, dendrites and cellular crystals in structure of the coating subject to heat treatment reduced significantly while isometric crystals increased. Meanwhile, grain growth, uni- form distribution of alloying elements as well as hardness in horizontal and vertical directions decreased to varying de- grees. Average microhardness in horizontal and vertical directions of the coating subject to solution treatment was HV350 and HV490 respectively; for that of the coating without solution treatment, HV520 and HV556 respectively. The hardness decreased while the structure was more uniformly distributed, and plasticity and comprehensive performance both in- creased. The application of heat treatment process to coating preparing and follow-up treatment has changed the mode of improving coating performance by simply relying on deposition parameters. Heat treatment is another way to improve the comprehensive performance of the Stellite6 alloy coating.