瓦楞辊现有强化方式如中频淬火、氮化、镀铬、激光相变硬化和喷涂碳化钨在寿命、成本、工艺稳定性及可再修复性方面存在一定的局限性,而采用激光熔覆的方法对瓦楞辊进行强化及修复可以在一定程度上弥补传统方法的劣势。针对瓦楞辊工况下强烈的低应力干摩擦磨粒磨损,采用专门研制的抗磨粒磨损粉末材料THW-64,通过工艺优化,在瓦楞辊齿表面激光熔覆制备厚度大于0.4 mm的耐磨涂层,研究瓦楞辊激光熔覆强化涂层的组织及性能。熔覆层无裂纹、与基体呈牢固的冶金结合, 涂层组织为亚共晶基体上弥散分布着大量原位生成的复合碳化物颗粒,平均显微硬度915HV0.2。摩擦学对比实验证明复合涂层耐磨粒磨损的性能明显改善,工业应用表明激光熔覆强化的瓦楞辊使用寿命较激光相变硬化有显著提高。

The present hardening technologies for corrugated rollers, such as intermediate frequency quenching, nitrogen hardening, chromeplate, laser transformation hardening and tungsten carbide spraying, have some limitation on cost, lifetime, technique stability and rejuvenation capability. Laser cladding offers an approach to improve the above comprehensive properties when hardfacing and repairing the corrugated rollers. This paper reported a laser cladded particulate reinforced composite coating by using a unique cladding powder material THW-64 to tackle the severe dry friction abrasive wear on corrugated roller surface. After laser cladding with optimized parameters, the crack-free coatings with thickness over 0.4 mm, have strong metallurgic bond with the substrate. The main microstructure of the coating consists of hypoeutectic matrix and many homogeneously distributed complex carbide particles with average hardness of 915HV0.2. Wear test and real production applications demonstrate that the abrasive wear resistance and working lifetime of corrugated rollers hardfaced by these particulate-reinforced composite coatings have been dramatically improved.