特定条件下的奥氏体不锈钢应力腐蚀开裂行为

Stress Corrosion Cracking Behavior of Austenitic Stainless Steel Under Special Conditions

文章研究了退火态1Cr18Ni9Ti奥氏体不锈钢在78±5℃的纯NaCl溶液和NH4Cl加NaCl混合溶液中的应力腐蚀行为。结果表明,在22%NaCl中试样经1000h试验不发生应力腐蚀开裂。而浸在3%NH4Cl加17%NaCl,5%NH4Cl加10%NaCl,5%NH4Cl加17%NaCl,5%NH4Cl加25%NaCl四种混合溶液的试样经过小于1000h就产生应力腐蚀裂纹或断裂,所以NH4Cl促进了1Cr18Ni9Ti钢在NaCl溶液中的应力腐蚀开裂。依据断口扫描形貌和裂纹扩展途径的金相观察,探讨了在混合溶液中应力腐蚀机制。

Here studied is the stress corrosion cracking behavior of annealed 1Cr18Ni9Ti austenitic steel in NaCl solution and a mixture of NH4Cl and NaCl at the temperature of 78 ± 5 ℃ . The tests show that the coupon shows no stress corrosion cracking after being placed in the 22% NaCl solution for 1000 hours, while its shows stress corrosion cracking when it is submerged in the four solutions of 3 % NH4 Cl and 17 NaCl 5 % NH4 Cl and 10 NaCl 5 % NH4 Cl and 17 NaCl and 5 % NH4 Cl and 25 NaCl for less than 1000 hours. This proves that NH4 Cl promotes the stress corrosion cracking of 1Cr18Ni9Ti stainless steel in NaCl solution. The stress corrosion mechanism of in mixed solutions is explored based upon metallographic analysis of crack development.