After the oil casing adopts this heat treatment method, it can effectively improve the impact toughness, tensile strength, and anti-destruction performance of the oil casing, ensuring a good value in use. Oil casing is a necessary pipe for drilling oil and natural gas, and it must have good performance in use. Different temperature controls are used for oil casing in different temperature ranges. The heating needs to be produced according to a certain temperature. The AC1=736°C and AC3=810°C of 27MnCrV steel should be selected for tempering after quenching. The holding time is 50 minutes; the heating temperature is selected between 740 and 810°C during sub-temperature quenching. The sub-temperature quenching selects a heating temperature of 780°C, and the holding time of quenching heating is 15 minutes. Since sub-temperature quenching is heated in the α+γ two-phase region, the quenching is carried out in the state of partially undissolved ferrite, and the toughness is improved while maintaining high strength. improve.
The heat treatment of oil casing must be strictly implemented to ensure that the produced oil casing has excellent product quality and performance, can show good use value and performance in use, adhere to high strength and toughness, and conduct heat treatment in different ways. At the same time, low-temperature quenching is lower than the conventional temperature, which reduces the stress of quenching and the deformation of quenching. This ensures the smooth operation of the production of oil casing heat treatment and provides a good foundation for subsequent wire processing. raw material.
At present, this process has been applied in different steel pipe processing plants. The quality assurance data shows that the tensile strength of the steel pipe after heat treatment is Rm910-940MPa, the yield strength Rt0.6820-860MPa is 100% qualified, and the impact toughness Akv65-85J data indicates that, 27MnCrV steel pipe is already a very high-quality high-grade steel oil casing. On the other hand, it also shows that the sub-temperature quenching process is an excellent method to avoid high-temperature brittleness in the production of steel products.
Hunan Gaoxing Steel Development Zone, No.1888 Purui South Rd, Wangcheng District,Changsha, Hunan, China