摘要
采用热-力学模拟实验方法研究了X70QS无缝管线钢管在不同冷却速度下的组织演化,并测试典型组织X70QS的力学性能、抗氢致开裂性能、抗硫化物应力开裂性能和动态腐蚀性能。结果表明,当冷却速度小于5℃/s时,X70QS钢的转变组织为PF+P。随冷却速度增大,粒状贝氏体组织的含量不断增加;当冷却速度达到40℃/s时,X70QS钢形成的组织为B粒+PF+P+MA。与组织类型为PF+P+MA的X70QS相比,B粒+PF+P+MA组织具有更好的强韧性。在严格控制带状组织和条状夹杂物形成的条件下,B粒+PF+P+MA组织类型的X70QS具有很好的抗HIC性能和抗SSCC性能。在模拟工况条件下,动态腐蚀速率也较小。
The microstructure transformation of X70QS grade seamless linepipe for sour service was investigated by thermal simulation method. The mechanical properties, resistance hydrogen-induced cracking （HIC）, sulfide stress corrosion （SSC） and dynamic corrosion for typical microstructure of X70QS were tested. The results show that the microstrueture of XTOQS is polygonal ferrite （PF） and pearlite （P）, when the cooling rate is less than 5℃/s. The transformation of grain bainite （GB） becomes more and more with the cooling rate increasing. The microstructure is grain bainite and polygonal ferrite, and a little pearlite and martensite-austenitic （MA） appear when the cooling rate arrives at 400C/s. Compared with PF＋P＋MA, the strength and toughness for GB＋PF＋P＋MA microstructure perform better. Furthermore, the microstructure of GB＋PF＋P＋MA has good resistance of HIC and SSC if the banded structure and large stripe inclusion are controlled severely. The rate of dynamic corrosion is small under simulating the actual environment of oil field.
出处
《热加工工艺》
CSCD
北大核心
2014年第6期84-87,90,共5页
Hot Working Technology
