A Review of Stress Corrosion Cracking of Welded Stainless Steels

摘要

This article gives a brief review of scientific researches of high-alloyed chromium-nickel steels stress corrosion cracking (SCC) process of welded joints. Welded joints are one of the most complex objects from the standpoint of the general theory of corrosion fatigue of metals. During their operation a number of problems arise related to the heterogeneity of the material properties, the complexity of the structure, the presence of structural and technological stress concentrators, residual stresses, etc. The characteristic features of corrosion cracking cited in the studies of Russian and foreign scientific schools are noted. The main types of corrosion damage at various sections of the welded joint are examined: corrosion of the weld metal, damage to the zones of thermal influence, knife damage occurring at the boundary between the joint and the base metal. The models of nucleation and development of cracks in the mechanism of Inter-granular corrosion (IGC) were analyzed. The article provides information on the causes of the steel’s propensity to Inter-granular corrosion. The data on the effect of heat treatment on the tendency of the weld metal to Inter-granular corrosion were systematized. The main regularities of corrosion-resistant alloying are noted. Data on the methods for preventing Inter-granular corrosion and reducing the tendency of the weld metal to stress corrosion cracking are given. Methods for estimating the tendency of weld metal to stress corrosion cracking are classified. The analysis of methods for preventing the tendency of welded joints to stress corrosion is given: metallurgical methods related to the effect on the chemical composition of the weld and the structure of the welded joint and technological methods associated with controlling the parameters of the welding and heat treatment regime.