热轧304不锈钢热浸镀铝工艺优化

Optimization of Hot-Dip Aluminizing Process of Hot-Rolled 304 Stainless Steel

不锈钢微弧氧化处理前需在其表面制备一层铝层,而目前热轧304不锈钢热浸镀铝工艺鲜见报道。对热轧304不锈钢进行热浸镀铝处理,采用正交试验优选了浸镀液成分、浸镀时间、温度以及助镀剂种类等工艺参数。采用金相显微镜观察镀层表面形貌和镀层组织,并测定镀层厚度。结果表明:最优工艺为采用Al-1.5%RE合金浸镀液和Cr2O3悬浊液助镀剂,800℃热浸镀5 min;最优工艺所得镀层表面光滑、无裂纹,表面镀层厚2.53 mm,过渡层厚0.51 mm,前者厚而后者薄,有利于后续微弧氧化陶瓷涂层的制备。

Orthogonal tests were conducted to optimize hot-dip aluminizing parameters including hot-dip bath composition,dipping time,dipping temperature and fluxing agent of hot-rolled 304 stainless steel.A metallurgical microscope was performed to observe the morphology and microstructure of as-prepared hot-dip aluminizing coatings and determine the thickness of the coatings as well.Results indicated that the optimized hot-dip aluminizing bath consisted of Al-1.5% rare earth alloy as well as a proper amount of Cr 2 O 3 as fluxing agent,while the optimized hot-dip aluminizing parameters were determined to be dipping temperature of 800 ℃ and dipping time of 5 min.The hot-dip aluminizing coating obtained under the optimized condition was smooth and free of cracks.The coating thickness and intermediate layer thickness were 2.53 mm and 0.51 mm,respectively,which was beneficial to follow-up preparation of micro-arc oxidation ceramic coatings.