高强度抽油杆用钢的腐蚀疲劳行为

研究了高强度抽油杆用钢３８ＭｎＣｒＮｉＭｏ经８９０°Ｃ×１ｈ空冷＋６０００Ｃ×１ｈ空冷（回火）及８９０°Ｃ×１ｈ空冷（正火）处理后，在空气、蒸馏水和３．５％ＮａＣｌ水溶液中的疲劳裂纹扩展速率（ＦＣＧＲ）及外加极化电位对ＦＣＧＲ的影响，并对腐蚀疲劳（ＣＦ）断口及金相组织进行了微观分析。结果表明，该钢经两种工艺热处理后在中性水溶液中疲劳裂纹扩展均属氢脆（ＨＥ）机制。由于回火样强度较低，塑性较好，对ＨＥ敏感性较低，所以具有较高的疲劳抗力，ＦＣＧＲ较低。文中就ＣＦ过程中裂纹扩展对ＨＥ的敏感性进行了讨论。

CORROSION FATIGUE BEHMIOUR OF A HIGH STRENGTH STEEL FOR OIL-DRAWING STICKS

Fatigue craCk.growth rates (FCGR)of tempered and normalized specimen of high strength steel38MnCrNiMo exposed to air,distilled water and 3.5%NaCl solution were evaluated. The effects of appliedpolarization potentials on FCGR in 3.5%NaCl solution were examined. The corrosion fatigUe fracturesurfaCe features and metallographic microstructure were also observed. The results indicated that thefatigue crack growth for the steel was controlled by hydrogen embrittlement(HE)and the FCGR oftempered specimens was lower than that of normalized specimens in air,distilled water and 3.5% NaCI' solution. The HE sensitivity of fatigue crack growth for the sted in corrosive environments was aLsodiscussed.