Simultaneous Chromizing and Aluminizing of Pure Iron and Cr - Mo Steel
김선규Sun Kyu Kim, 신원순Won Soon Shin
Abstract
A simultaneous chromizing-aluminizing coating process was developed using pure iron, and Cr-Mo alloy as substrate. In order to deposit Cr and Al simultaneously, the activities of Cr and Al should be controlled which means the composition of the Cr-Al masteralloy should be adjusted. The optimum composition of the Cr-Al masteralloy was calculated to be 90 wt%∼95wt% Cr, 5wt%∼10wt% Al using the SOLGASMIX computer program. Simultaneous chromizing and aluminizing of the pure iron and the Cr-Mo steel was performed using the master alloy powder of 95Cr-5Al wt% and NH₄Cl as an activator at the temperature range of 1223K-1323K under Ar atomosphere. NH₄Cl was found to be a better activator than NaCl and the optimum composition was 3wt% NH₄Cl.