The effectiveness of acid pickling of stainless steel (SS) depends largely on the composition and structure of the scale formed on the surface. These properties are affected by the type of stainless steel considered and also by the heating atmosphere in which the stainless steel exposed. In this investigation, the compositions and structures of scales formed on 410 SS surface after exposing in dry air, moist air, N2 and 10%H2+N2 atmospheres are analyzed. The results show that the scale formed in the moisture containing air is the most difficult to be removed, while descaling becomes much easy if the stainless steel is heated in reducing atmosphere (10%H2+N2). The effectiveness of descaling can be predicted by measuring the potential change during acid pickling. The determination of the reactivation time in the potential decay curves is found to be an effective way for end-point detection of acid pickling of 410 SS in H2SO4 electrolyte.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Materials Science(all)