After the oil casing adopts this heat treatment method, the impact toughness, tensile strength, damage resistance, etc. of the oil casing can be very effectively improved, ensuring good value in use. Oil casing is a necessary pipe material for drilling oil and natural gas, and it must have good performance during use. Petroleum casing uses different temperature controls in different temperature sections. Heating needs to be produced according to a certain temperature. AC1=736℃ and AC3=810℃ for 27MnCrV steel. The tempering temperature selected after quenching should be 630℃. Tempering heating The holding time is 50 minutes; during sub-temperature quenching, the heating temperature is selected between 740 and 810°C. The heating temperature for sub-temperature quenching is 780°C, and the holding time for quenching heating is 15 minutes. Since sub-temperature quenching is heated in the α+γ two-phase region, quenching is performed while preserving the partially undissolved ferrite. While maintaining high strength, the toughness is improved. improve.
The heat treatment of oil casing must be strictly implemented to ensure that the produced oil casing has excellent product quality and performance and can show good use value and performance during use. It must maintain high strength and toughness and perform heat treatment in different ways. At the same time, the low-temperature quenching temperature is lower than the conventional temperature, which reduces the quenching stress and reduces the quenching deformation. This ensures the smooth operation of the production of oil casing heat treatment and provides good conditions for subsequent wire processing. raw material.
At present, this process has been applied in pipe processing plants of different steel pipes. The quality assurance data shows that the tensile strength of the heat-treated steel pipe is Rm910-940MPa, the yield strength is Rt0.6820-860MPa, and the damage resistance is 100% qualified. The impact toughness Akv65-85J data indicates that 27MnCrV steel pipe is already a very high-quality high-grade petroleum 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.
Post time: Dec-18-2023