パルプ，染色，漂白工業用不銹鋼の研究（第3報）

Abstract

The immersion corrosion test were carried out on five kinds of austenitic stainless steels. The specimens were alloys of 23% Cr-20% Ni-1.5% Cu-1.5% Si-0.5% Mn, 23% Cr-20% Ni-2% Si-0.5% Mn, 23% Cr-20% Ni-3% Mo-3% Cu-0.5% Mn (clumin M3MC), 20% Cr-23% Ni-1.4% Mo-1.4% Cu-3% Si-0.5% Mn and 23% Cr-20% Ni-3% Mo-3% Cu-2% Si-0.5Mn. The corrosives were aqueous solutions of HCl, H2SO4, HNO3, CH3COOH, (COOH)2, HCOOH, Al2(SO4)3 Ca(OCl)2 and FeCl3 at 27°C and boiling aqueous solutions of HCl, H2SO4 and mixture of H2SO4 and HNO3.Results are as follows. (i) Alloys of 20% Cr-23% Ni-1.4% Mo-1.4% Cu-3% Si-0.5% Mn, 23% Cr-20% Ni-3% Mo-3% Cu-0.5% Mn had good acid-resistivities against HCl at 27°C temperature. (ii) All alloys were not been attacked at all in H2SO4, HNO3, CH3COOH, (COOH)2, HCOOH and aqueous solutions of Al2(SO4)3 and Ca(OCl)2 at a constant temperature. (iii) Alloys of 23% Cr-20% Ni-3% Mo-3% Cu-2% Si-0.5% Mn and 23% Cr-20% Ni-3% Mo-3% Cu-0.5% Mn had good acid-resistivities against HCl at boiling points. (iv) Alloys of 23% Cr-20% Ni-3% Mo-3% Cu-0.5% Mn and 20% Cr-23% Ni-1.4% Mo-1.4% Cu-3% Si-0.5% Mn and 23% Cr-20% Ni-3% Mo-3% Cu-2% Si-0.5% Mn were not attacked at all in mixture of H2SO4 and HNO3 at boiling points.