渗铝钢渗铝层中孔隙及裂纹对其耐高温SO2腐蚀性能的影响

研究了热浸渗铝工艺参数及铝液中添加合金元素对渗铝钢渗铝层孔隙及裂纹的影响,并对不同孔隙的渗铝层进行了SO2气氛腐蚀试验。结果表明:裂纹随扩散工艺条件的改变,变化不明显;在渗铝液中添加w(Cr)1.5%或w(Ce)0.5%,在850~950℃的扩散温度,渗铝层的孔隙达到标准1~3级合格要求;在φ(N2)80%,φ(O2)10%,φ(SO2)10%气氛中,600℃恒温条件下腐蚀168 h,渗铝层孔隙稍有增加,950℃扩散的渗铝层耐SO2腐蚀性能好,加Ce渗铝层耐腐蚀性能最优。

Effect of pores and cracks in aluminized layer of aluminized steel on its resistance to high temperature SO2 gas corrosion

The influence of the parameters of hot-dip aluminizing process and the addition of alloy elements to the aluminizing liquid on the porosity and crack of aluminizing layer of aluminizing steel are studied. The SO2 atmosphere corrosion test is carried out on the aluminizing layer with different porosity. The results show that the cracks do not change obviously with the change of diffusion process conditions;when w(Cr) 1.5% or w(Ce) 0.5% is added to the aluminizing liquid and the diffusion temperature is 850-950 ℃, the pore of aluminizing layer meets the requirements of 1-3 grade;under the atmosphere of φ(N2)80%,φ(O2)10%,φ(SO2)10%, corrosion at 600 ℃ for 168 h, he porosity of aluminized layer slightly increased, the diffusion aluminizing layer has good SO2 corrosion resistance, and Ce aluminizing layer has the best corrosion resistance.