Investigation on AISI 304 austenitic stainless steel to AISI 4140 low alloy steel dissimilar joints by gas tungsten arc, electron beam and friction welding

Microstructure and stress corrosion cracking of the fusion boundary region in an alloy 182-A533B low alloy steel dissimilar weld joint

An assessment for mechanical and microstructure behavior of dissimilar material welded joint between nuclear grade martensitic P91 and austenitic SS304 L steel

The susceptibility to stress corrosion cracking (SCC) of type 321 stainless steel (type 321s) in a simulated petrochemical process environment containing hydrogen sulfide and chloride (20 wt.% NaCl + 0.01 M Na2S2O3, pH 2) was assessed using the slow strain rate tensile (SSRT) test and static load (U-bend) tests at the free corrosion potentials. In the SSRT, effects of environmental factors, such as chloride (Cl−) plus thiosulfate (S2O32−), Cl− concentration, solution pH, and temperature, on the susceptibility to SCC of type 321s were critically examined. In addition, factorial design experiments using Yates's algorithm quantitatively estimated the individual and interactive effects of temperature, Cl− concentration, and solution pH on the SCC susceptibility of type 321s. In the U-bend tests, specimens were immersed in an autoclave containing deaerated 20 wt.% NaCl + 0.01 M Na2S2O3 aqueous solution (pH 2) for 1400 h at either 80 or 300 °C. Results of the SSRT tests indicated that the effects of environmental factors on the SCC susceptibility of type 321s decreased in the following order: temperature effect ≫ solution pH effect > Cl− concentration effect. The mechanism of SCC induced by corrosion pits or TiC particles (5–10 μm) is discussed. In addition, results of the U-bend tests show that the susceptibility of type 321s to SCC decreases with increasing temperature, which is related to the more compact surface film containing chromic oxide (Cr2O3) and magnetite (Fe3O4) that forms at the higher temperatures.

G.F Li

Papers

Effect of post weld heat treatment on stress corrosion cracking of a low alloy steel to stainless steel transition weld