Abstract
Effects of solution annealing condition, homogenizing, cold or hot rolling, aging, and the combination of cold rolling and aging were investigated on the corrosion resistance of Fe-18%Cr-14%Ni-0.5%Si-1.0%Mn alloys containing 100 ppm of C, P and S in concentrated boiling nitric acid. It was found that the corrosion resistance of Fe-18%Cr-14%Ni-0.5%Si-1.0%Mn alloys was remarkably degraded by the combined effect of 30% cold rolling and aging at 973 K, although neither cold rolling nor aging showed much influence on the corrosion resistance of the alloys. It was suggested that the degradation of corrosion property was induced by P segregation to grain boundaries of the alloys from the investigations into the micro-structural change and the impurity effect.
It was also shown that Fe-18%Cr-14%Ni-0.5%Si-1.0%Mn alloys had superior corrosion resistance to SUS 304 L stainless steel in boiling 5 kmol/m3 nitric acid containing highly oxidizing ions.
