Cr12钢稀土盐浴渗铬试验研究

在选定供铬剂、还原剂的条件下,对影响盐浴渗铬效果的基盐配比、稀土和活化剂加入量进行配方正交试验,通过对Cr12钢试样盐浴渗铬工艺及渗层厚度的分析比较,筛选出900℃×4 h盐浴渗铬时的最优配方;采用光学金相观察、显微硬度测试、砂浆磨损试验等方法,分析比较了Cr12钢样品加稀土前后渗层厚度、硬度分布及相对耐磨性等性能。研究表明,添加稀土对盐浴渗铬有明显催渗作用,渗铬样品在渗层厚度、硬度梯度分布及耐磨性方面均优于未加稀土的渗铬样品和Cr12钢900℃加热油冷样品;添加适量NaCl和NaF以改造硼砂基盐配方,对改善熔盐流动性、降低挥发等方面产生了良好效果。

Experimental study of rare earth salt-bath chromizing for Cr12 steel

An orthogonal test was carried out based on study of three factors influencing salt-bath chromizing,such as proportion of mixed base salt and addition amount of activator and RE;then an optimum recipe was selected which makes a greatest thickness of layer and a better process in 900 ℃×4 h salt bath chromizing.Metallographic optical microscope,microhardness test and friction and wear experiment were used to compare the diffusion layer thickness,hardness distribution,relative wearability between the salt bath formula with and without RE.Study shows that rare earth plays a significant role in salt-bath chromizing;and adding proper amount of NaCl and NaF is helpful for improving the liquidity of salt-bath.