中厚壁X65Q管线管热处理工艺研究

Study on Heat Treatment Process of X65Q Line Pipe with Medium Thick Wall

对中厚壁X65Q无缝钢管进行了不同热处理工艺制度的工业试验,并对材料的组织、性能进行了检测分析。试验结果表明:生产的Ф406.4 mm×26.19 mm规格X65Q无缝钢管,经过内喷、外淋水量均为3 300 m3/h淬火后,钢管由内壁至心部,马氏体含量逐渐减少,钢管内表面组织为回火索氏体+贝氏体组织,外表面组织为贝氏体组织;淬火后经过630℃回火,材料晶粒度达8.5级,0℃横向冲击值达200 J以上,屈服强度达500 MPa以上,实现了材料强度、韧性良好匹配,满足API 5L标准要求。

In this paper, the industrial experiments of different heat treatment processes for X65Q seamless steel tube with medium thick wall are carried out as well as its microstructure and properties are tested and analyzed. The test results showed that the martensite content of X65Q seamless steel tube with specification of Ф406.4 mm×26.19 mm was gradually reduced from inner wall to center after quench with 3 300 m~3/h inner and outer spraying as well as the microstructure of its internal surface was tempered sorbite+bainite, microstructure of its outer surface was bainite;after quenching, its grain size reached grade 8.5, transverse impact value at 0 ℃ reached over 200 J and yield strength reached over 500 MPa with tempering of 630 ℃ so that the strength and toughness of material matched well, which could meet the requirements of API 5L standard.