冷加工对800合金抗碱性应力腐蚀破裂的影响

采用Ｃ形环恒电位ＳＣＣ试验，研究了喷丸和机械胀管两种冷加工对８００合金ＳＣＣ敏感性的影响。结果表明经过３种玻璃喷丸处理的管件的抗碱性ＳＣＣ性能比未喷丸的光管好，抗ＳＣＣ性能随表面压力的增大而增强；机械胀管使８００合金管的抗碱性ＳＣＣ性能下降，当胀管率超过１５％时，ＳＣＣ裂纹萌生时间迅速缩短，开裂速度大大加快，胀管率较大的开裂裂纹为ＴＧＳＣＣ或ＴＧ＋ＩＧＳＣＣ，而胀管率较小的ＩＧＳＣＣ。

EFFECT OF COLD WORK ON THE CAUSTIC STRESS CORROSION CRACKING OF ALLOY 800

The effect of two cold working factors i. e. shot peening and mechanically expanding tubes on the caustic stress corrosion cracking (SCO of alloy 800 was investigated using C-ring tests at controlled potential-s. Shot peening of alloy 800 tube gave rise to an increase of resistance to caustic SCC, which was related to an in-crease of compressive stress in the surface. The mechanically expanding tube operation was detrimental to the SCC resistance of alloy 800 tubes in the caustic solution. Once the expanding ratio exceeded ca. 15% , the initiation time of SCC cracks was shortened quickly, and the growth of SCC cracks was accelerated. When the expanding ratio was large, the crack mode was TGSCC or TG + IGSCC, while the ratio was small, the mode was IGSCC.