2013 年 81 巻 8 号 p. 623-626
Stainless steel is preventive enough against rust, and is widely put to practical use because of the excellence in its material in aspects of sanitation. Junctions of the material change their color owing to high temperature in carrying out joining work by arc-welding. By performing the analysis of the portions where colors are changed and its execution together with high temperature accompanied with weldment, iron is isolated to be changed in its color. Based upon these results, a reagent with both higher safety and higher removal rate than conventional chemicals allowing change of color to be removed has been developed.