發(fā)布時間：2018-05-14 17:18

  本文選題：NG焊接接頭 + 應(yīng)力腐蝕開裂(SCC)　； 參考：《核動力工程》2017年01期

【摘要】：通過慢應(yīng)變速率拉伸(SSRT)試驗和高溫電化學(xué)相結(jié)合的方法,研究外加電位對奧氏體不銹鋼316NG焊接接頭在含氯離子的高溫高壓水中應(yīng)力腐蝕開裂(SCC)傾向的影響。試驗結(jié)果表明:退火態(tài)316NG焊接接頭SCC敏感性隨外加電極電位升高而增大,且存在一個介于+50~+100 mV[相對標(biāo)準(zhǔn)氫電極(vs.SHE)]之間的SCC臨界電位;低于該電位時,SCC敏感性較小,無明顯沿晶開裂,僅斷口邊緣處存在少量穿晶開裂,隨電極電位變化不明顯;高于該臨界電位時,SCC敏感性急劇增加,并出現(xiàn)明顯的沿晶開裂。此外,高溫Ar和腐蝕性低(電極電位≤50 mV)的環(huán)境中,焊接接頭的斷裂為力學(xué)主導(dǎo)的塑形開裂,其與焊接接頭的硬度分布密切相關(guān),硬度越低,越容易斷裂;強腐蝕性(電極電位50 mV)環(huán)境中,焊接接頭的斷裂為腐蝕主導(dǎo)的脆性開裂;顯然,焊縫及熱影響區(qū)的SCC敏感性高于母材。
[Abstract]:The effect of applied potential on the stress corrosion cracking (SCC) tendency of austenitic stainless steel 316NG welded joints in high temperature and high pressure water containing chloride ions was studied by means of slow strain rate tensile test and high temperature electrochemical method. The experimental results show that the SCC sensitivity of annealed 316NG welded joints increases with the increase of the applied electrode potential, and there exists a critical SCC potential between 50 ~ 100mV [relative to the standard hydrogen electrode vs.Shee]. There was no obvious intergranular cracking, only a small amount of transgranular cracking occurred at the edge of the fracture surface, which did not change significantly with the electrode potential, and the sensitivity of SCC increased sharply when the critical potential was higher than the critical potential, and obvious intergranular cracking occurred. In addition, in the environment of high temperature ar and low corrosion (electrode potential 鈮，

本文編號：1888786