添加稀土铈对热浸镀铝45钢的组织及其性能的影响

Effects of Rare Earth Element Cerium on the Microstructure and Properties of Hot-dip Aluminum Coatings on 45 Steel

采用SEM和XRD研究了添加不同含量铈对45钢基热浸镀铝镀层及其退火后的组织和结构影响,并用氧化增重法考察了镀层的耐热性,用M-2000型摩擦磨损试验机测试了镀层退火后的耐磨性能。结果表明,镀液中稀土铈质量分数为0.1%~0.25%时,镀层晶粒细化、厚度降低,退火合金层厚度增加。稀土铈能抑制合金层的Fe2Al5相生长,使镀层合金层以FeAl3、少量Fe2Al5相为主,使退火合金层以FeAl、Fe3Al相为主。稀土铈含量为0.25%时,镀层的抗高温氧化性和镀层退火后在油润滑下的耐磨性最佳。

The influences of element cerium on the microstructure and properties of hot-dip aluminum（HDA） coatings on 45 steel were studied by scanning electron microscopy（SEM） and X-ray diffractometry（XRD）.The high-temperature oxidation resistance and wear properties of HDA coatings were also evaluated by oxidation weight increase method and using the MM-2000 wear tester,respectively.The results show that grains of HDA coatings are refined and the layer thickness becomes thinner when Ce content is between 0.1 wt.% and 0.25 wt.%.At the same time,the alloy layer of HDA coatings treated by annealing becomes thicker.Ce could restrain the growth of Fe_2Al_5 in the alloy layer.As a result,the alloy layer of HDA coatings consists of FeAl_3 and a little Fe_2Al_5,but the annealed alloy layer consists of FeAl and Fe_3Al.The high-temperature oxidation resistance of HDA coatings and the wear resistance of the annealed alloy layer under oil lubrication are the best when Ce content is 0.25 wt.%.