Zhang Yinqiao,Kong Fange,Zhang Jihong,et al.Microstructure and Properties of 12Cr1MoVG Thick-wall Steel Pipe with High Temperature Normalizing + Tempering[J].Special Steel,2023,44(04):102-107.
Zhang Yinqiao,Kong Fange,Zhang Jihong,et al.Microstructure and Properties of 12Cr1MoVG Thick-wall Steel Pipe with High Temperature Normalizing + Tempering[J].Special Steel,2023,44(04):102-107. DOI: 10.20057/j.1003-8620.2023-00043.
Microstructure and Properties of 12Cr1MoVG Thick-wall Steel Pipe with High Temperature Normalizing + Tempering
Microstructure and properties of Φ457 mm×70 mm 12Cr1MoVG steel pipe (/% : 0.13C, 0.21Si, 0.56Mn, 1.07Cr, 0.31Mo, 0.20V, 0.008P, 0.004S, 0.02Ni, 0.004Cu, 0.012 4Al) after 1 000 ℃ normalizing plus using water mist accelerated cooling and 740 ℃ tempering were studied by means of microstructure observation, tensile test , impact test at room temperature, hardness test and high temperature durability test. The results showed that the microstructure consisted of ferrite and bainite, with the volume of bainite accounting for 65%, and the grain size of 7-5 grade. Yield strength was 416 MPa, tensile strength was 575 MPa, impact energy at room temperature was 206-244 J, brinell hardness was 187HBW. The endurance strength under 575 ℃×10
5
h was 86 MPa. It lasted 51 480 hours at 575 ℃/100 MPa unbroken. After 27 198 hours, it cracked under 575 ℃/120 MPa, and the crack originated from grain boundary creep pores, no serious spheroidization was found in the bainite matrix surrounding. The structure stability was excellent.