What Is The Oil Casing Pipe Equipment?

　　27MnCrV is a new type of steel used to produce tp110t steel grade petroleum pipe sleeve, and 29crmo44 and 26crmo4 are used to produce tp110t steel grade petroleum pipe sleeve. Compared with the latter two, 27MnCrV contains less Mo, which can greatly reduce the production cost. However, there is obvious high temperature temper embrittlement after 27MnCrV is produced by normal austenitizing and quenching process, resulting in low impact toughness and instability.

　　To solve these problems, two methods are usually used: one is to use rapid cooling after tempering to avoid high temperature brittleness and obtain toughness. Second, L80, N80, P110 Ltc Oil Casing Pipe the sub temperature quenching method can effectively improve the harmful elements and impurities and improve the toughness through the incomplete austenitizing of steel grades. In the first method, the requirements for heat treatment equipment are relatively strict, and additional costs need to be added.

　　For 27MnCrV steel, AC1 = 736 ℃, AC3 = 810 ℃, and the heating temperature for sub temperature quenching is between 740-810 ℃. The heating temperature of 780 ℃ is selected for sub temperature quenching, and the holding time of quenching heating is 15min; the tempering temperature of 630 ℃ is selected for tempering after quenching, and the holding time of tempering heating is 50min. Because the sub temperature quenching is heated in the α + γ two-phase region, and the quenching is carried out under the condition of keeping part of undissolved ferrite, the toughness is improved while maintaining high strength.

　　At the same time, the low temperature quenching reduces the stress of quenching and the deformation of quenching, which ensures the smooth operation of heat treatment production, and provides a good raw material for subsequent wire turning.

　　The process has been applied in the processing plant. The quality assurance data show that the yield strength, tensile strength and impact toughness of the steel pipe after heat treatment are respectively 820-860mpa, 910-940mpa, 65-85j and 100% qualified. The data show that 27MnCrV steel pipe has been a high quality oil casing of high steel grade. On the other hand, it shows that the sub temperature quenching process is an excellent method to avoid high temperature brittleness in steel production.