Stress Corrosion Cracking of Chromium-containing High Manganese Austenitic Steels

Abstract

Effect of several factors on the IGSCC susceptibility of chromium-containing high manganese austenitic steels has been investigated. As a result, a corrosion resistant high manganese steel to IGSCC has been developed. The mechanism of IGSCC is discussed.
0.4%C-18%Mn-5%Cr steel posesses the susceptibility to IGSCC at HAZ of weldment. The steel heat treated at temperatures from 500 to 900°C shows the susceptibility. IGSCC of the alloy is possible to occur even in pure water as well as in chloride solution. However, solution treatment above the temperature of 950°C prevents the alloy from IGSCC. Chromium depleted zone at grain boundary associated with the precipitation of chromium carbide (Cr₂₃C₆) is seemed to be prefferentially attacked resulting in IGSCC in corrosive media. The prevention of 0.4%C-18%Mn steel from IGSCC is possible to attain if the Cr content lowers below 2.5%.