Stress corrosion crack of 16Mn steel in wet sulfureted hydrogen environment

Stress corrosion cracking(SCC) behaviors of 16Mn and 16Mn(HIC) steels and their welded samples in acid H₂S solution are investigated, with slow - strain - rate test(SSRT) and U - bent - specimen test. The result shows that both 16Mn(HIC) steel and 16Mn steel as well as their welded joint materials are all easy to subject to SCC damage in NACE solution, and the cracks of all specimens are HIC - induced transgranular cracks. The resistance to SCC of 16Mn(HIC) steel is better than that of 16Mn steel, as well as the behavior of weld joint of 16Mn(HIC) steel also performs better than that of 16Mn steel; the susceptivities of welded specimens of these two kinds of steel are much higher than those of their base materials, and heat treatment can improve the abilities of welded joint materials to resist SCC.