核电站用42CrMoE螺栓材料超高周疲劳性能研究
|
摘要
鉴于地脚螺栓对保障核电站安全运行具有重大的工程意义,采用超声疲劳实验研究了核电站用42Cr Mo E螺栓材料的超高周疲劳性能。通过扫描电镜分析了不同疲劳阶段的断口形貌。结果表明,核电站用42Cr Mo E螺栓材料组织主要由回火索氏体组成,含少量铁素体。其S-N曲线为连续下降型,在10~9循环周次内不存在传统S-N曲线的水平平台,疲劳极限消失。而其对应于10~9周次下,疲劳强度为506 MPa。42Cr Mo E螺栓材料疲劳裂纹在高周和超高周范围内有相同的裂纹萌生机制,均是在试样表面的材料缺陷处萌生,局部存在夹杂物应力集中现象。当疲劳周次较高时,在靠近裂纹源处有更严重的氧化和腐蚀;随着循环次数的增多,疲劳辉纹变密集,间距减小。
In view of the great engineering significance of anchor bolts in the safe operation of nuclear power plants, the ultra-high cycle fatigue behavior of 42 Cr Mo E bolt material for nuclear power plants was investigated by the ultrasonic fatigue test. The fracture morphology of the specimens at different fatigue stages was analyzed by SEM. The results indicate that42 Cr Mo E bolt material for the nuclear power plant is mainly composed of tempered sorbite, with a small amount of ferrite. Its S-N curve is continuous descending type, and no traditional horizontal platform appears in the S-N curve within 10~9 cycles, so,there is no fatigue limit. Under 10~9 cycles, the fatigue strength is 506 MPa. 42 Cr Mo E bolt material has the same crack initiation mechanism in the range of high and ultra-high cycles, all cracks initiate at the defects on the surface of the specimens, and the stress concentration phenomenon appears around the inclusions. When the fatigue cycle is higher, there are more oxidation and corrosion near the crack source. Besides, with the number of the cycles increase, the fatigue striations become dense and the spacing becomes small.
In view of the great engineering significance of anchor bolts in the safe operation of nuclear power plants, the ultra-high cycle fatigue behavior of 42 Cr Mo E bolt material for nuclear power plants was investigated by the ultrasonic fatigue test. The fracture morphology of the specimens at different fatigue stages was analyzed by SEM. The results indicate that42 Cr Mo E bolt material for the nuclear power plant is mainly composed of tempered sorbite, with a small amount of ferrite. Its S-N curve is continuous descending type, and no traditional horizontal platform appears in the S-N curve within 10~9 cycles, so,there is no fatigue limit. Under 10~9 cycles, the fatigue strength is 506 MPa. 42 Cr Mo E bolt material has the same crack initiation mechanism in the range of high and ultra-high cycles, all cracks initiate at the defects on the surface of the specimens, and the stress concentration phenomenon appears around the inclusions. When the fatigue cycle is higher, there are more oxidation and corrosion near the crack source. Besides, with the number of the cycles increase, the fatigue striations become dense and the spacing becomes small.
引文
[1]李小泉,吕云飞,赵海新,等.42Cr Mo钢曲轴断裂失效分析[J].热加工工艺,2014,43(2):217-218.
[2]Quan G Z,Li G S,Chen T,et al.Dynamic recrystallization kinetics of 42Cr Mo steel during compression at different temperatures and strain rates[J].Materials Science and Engineering A,2011,528(13):4643-4651.
[3]余兆新,蒋佩华,姚志江,等.42Cr Mo钢螺栓断裂分析[J].金属热处理,2012,37(4):134-136.
[4]张继明,杨振国,张建锋,等.零夹杂42Cr Mo高强钢的超长寿命疲劳性能[J].金属学报,2005,41(2):145-149.
[5]Kang G,Liu Y.Uniaxial ratchetting and low-cycle fatigue failure of the steel with cyclic stabilizing or softening feature[J].Materials Science and Engineering A,2008,472(1):258-268.
[6]Kang G,Liu Y,Ding J,et al.Uniaxial ratcheting and fatigue failure of tempered 42Cr Mo steel:Damage evolution and damage-coupled visco-plastic constitutive model[J].International Journal of Plasticity,2009,25(5):838-860.
[7]许世文,董满生,胡宗军,等.42Cr Mo钢疲劳实验研究[J].合肥工业大学学报:自然科学版,2008,31(9):1506-1508.
[8]杨振国,张继明,李守新,等.42Cr Mo VNb细晶高强钢的疲劳行为[J].金属学报,2004,40(4):367-372.
[9]刘忠杰,邵尔玉.42Cr Mo钢混合组织与单一回火索氏体组织接触疲劳性能的研究[J].机械工程材料,1993(5):14-19.
[10]高玉魁,王仁智,姚枚,等.金属疲劳极限与静强度的相关性[J].机械强度,2001,23(1):15-18.
[11]邓海鹏,何柏林,于影霞,等.钢铁材料超高周疲劳的研究进展[J].热加工工艺,2017,46(4):6-12.
[2]Quan G Z,Li G S,Chen T,et al.Dynamic recrystallization kinetics of 42Cr Mo steel during compression at different temperatures and strain rates[J].Materials Science and Engineering A,2011,528(13):4643-4651.
[3]余兆新,蒋佩华,姚志江,等.42Cr Mo钢螺栓断裂分析[J].金属热处理,2012,37(4):134-136.
[4]张继明,杨振国,张建锋,等.零夹杂42Cr Mo高强钢的超长寿命疲劳性能[J].金属学报,2005,41(2):145-149.
[5]Kang G,Liu Y.Uniaxial ratchetting and low-cycle fatigue failure of the steel with cyclic stabilizing or softening feature[J].Materials Science and Engineering A,2008,472(1):258-268.
[6]Kang G,Liu Y,Ding J,et al.Uniaxial ratcheting and fatigue failure of tempered 42Cr Mo steel:Damage evolution and damage-coupled visco-plastic constitutive model[J].International Journal of Plasticity,2009,25(5):838-860.
[7]许世文,董满生,胡宗军,等.42Cr Mo钢疲劳实验研究[J].合肥工业大学学报:自然科学版,2008,31(9):1506-1508.
[8]杨振国,张继明,李守新,等.42Cr Mo VNb细晶高强钢的疲劳行为[J].金属学报,2004,40(4):367-372.
[9]刘忠杰,邵尔玉.42Cr Mo钢混合组织与单一回火索氏体组织接触疲劳性能的研究[J].机械工程材料,1993(5):14-19.
[10]高玉魁,王仁智,姚枚,等.金属疲劳极限与静强度的相关性[J].机械强度,2001,23(1):15-18.
[11]邓海鹏,何柏林,于影霞,等.钢铁材料超高周疲劳的研究进展[J].热加工工艺,2017,46(4):6-12.