Abstract
The corrosion tests of mild steel, 15% Si iron, 13% Cr steel, 30% Cr steel and 18-8 Cr-Ni steel were carried out by dip method. The corrosion resistance was examined in 5_??_98% HNO3 at 30_??_70° by measuring the weight loss for 10 hours, and the corrosion rate was expressed as g/m2 hr.
The results obtained are as follows. (1) Mild Steel; the resistivity of mild steel against conc. HNO3 is small. (2) 15%Si Iron; the resistivity is excellent, though this iron is slightly corroded in dil. HNO3. (3) 13%Cr Steel; this steel is corroded in dil. HNO3, but against 40_??_60% HNO3 the resistivity is fairly, good, and in more conc. HNO3 this steel is corroded slightly. (4) 30% Cr Steel; the resistivity of 30% Cr steel is excellent. (5) 18-8 Cr-Ni Steel; the resistivity of this steel is excellent, though this steel is slightly corroded in conc. HNO3 at 70°
