Abstract
Effect of cold work on intergranular stress corrosion cracking (IGSCC) of SUS 304 and SUS 304L was investigated in high temperature pure water, and the results were compared with intergranular corrosion behaviors by H2SO4-CuSO4 test. The results obtained are as follows: 1) Sensitization temperature-time region of SUS 304 where IGSCC occurs is greatest around 5 to 10% cold work, and this region becomes smallerr again at the higher cold work level. The susceptibility to IGSCC of SUS 304 which is cold worked and subsequently sensitized for a short time is much higher than that without cold work. 2) Cold work of 5 to 10% reduction accelerates chromium carbide precipitation along grain boundaries, but at the higher cold work level the carbides precipitate at slip bands as well as grain boundaries. The effect of cold work on IGSCC can be satisfactorily explained on the basis of these carbide precipitation behaviors. 3) Deformation induced martensite in SUS 304 increases the resistance to cracking, which is considered to be due to the metallurgical and electrochemical effects. 4) SUS 304L is much resistant to cracking compared with SUS 304. 5) The susceptibility to IGSCC in high temperature pure water does not necessarily agree with that to intergranular corrosion by H2SO4-CuSO4 test.
