Abstract
Effect of P content on stress corrosion cracking (SCC) has been studied for SUS304 stainless steel in high temperature water at 562K. SCC test was carried out using slow strain rate testing (SSRT) technique at 4.17×10-6s-1.
For the solution-treated specimens with 0.008%P to 0.10%P, the corrosion rate by Huey test increased with increasing P content, and that correlated with segregation of P at the grain boundaries. But, intergranular stress corrosion cracking (IGSCC) hardly occured.
The precipitation of M23C6 by sensitization treatment at 723K increased with increasing P content, Because it is considered that phosphorus was inserted in the M23C6, and carbides precipitated as M23(C, P)6.
IGSCC in high temperature water increased with increasing P content, because of the increase of M23(C, P)6 at the grain boundary.
The specimens sensitized after solution treatment at 1373K occured IGSCC more than that at 1573 K, because of the increase of M23(C, P)6 at the grain boundary.
