SUS 304鋼의 SCC 傳播特性에 關 한 硏究 = An Investigation of Stress Corrosion Cracking Propagation Characteristics of SUS 304 Stainless Steel

국문 초록 (Abstract)

定變位引長試驗機를 利用하여 SUS 304 鋼의 SCC 傳播特性을 여러가지 Mgcl₂溶液 中에서 硏究한 結果 다음과 같은 結論을 얻었다.
1) 용접열 영향부의 SCC 傳播는 모재보다 용접열 사이클로 因한 銳敏化 현상에 의해 빨라진다.
2) 용접열 영향부의 SCC 傳播는 主 균열과 미세 균열로 성장하다가 主균열은 ?? 결핍 영역으로 계속 성장되고 미세 균열은 정지된다.
3) 비등 Mgcl₂溶液의 농도가 30%(wt)以下에서는 SCC 傳播가 크게 둔화된다.
4) 42%(wt) 비등 Mgcl₂溶液에서는 初期 SCC 傳播 速度가 빨라지고 같은 농도에서 온도를 115℃로 낮추면 初期 SCC 傳播 速度가 지연된다.

다국어 초록 (Multilingual Abstract)

The characteristics of SCC propagation of SUS 304 stainless steel were studied with the specimens of the constant displacement type under the environment of various Mgcl₂ aqueous solutions.
Main results obtained as follows;
1) SCC propagation of weld heat affected zone has a rapid growth for phenomenon of sensitizing caused by weld heat cycles than that of base metal.
2) SCC propagation of weld heat affected zone has a growth with main and minute
cracks, where main crack is grown in to chromium depleted zone, but minute crack
stops growing.
3) SCC propagation has a slow growth when the concentration of Mgcl₂boiling
solution is bellow 30%(wt).
4) Initial crack growth rate of SCC is rapidly propagated under 42%(wt) Mgcl₂ boiling solution of 143℃, but slowly propagated under the temperature of 115℃ lower than that of 42%(wt)Mgcl₂boiling solution.