Heat treatment technology of oil casing

Posted by zora li on August 29th, 2022

After the seamless steel casing pipes is heat treated, it can effectively improve the impact toughness, tensile strength, and damage resistance of the oil casing, ensuring good value in use.

Petroleum casing is a commonly used pipe for drilling oil and natural gas, and it needs to have good performance during use. Different temperature control is used in different temperature sections for oil casing. Heating needs to be produced according to a certain temperature. K55 oil casing material steel has AC1=736℃, AC3=810℃, and the tempering temperature after quenching is 630℃. The heating temperature is selected between 740-810℃ during sub-temperature quenching for 50min. The heating temperature of sub-temperature quenching is 780℃, and the holding time of quenching heating is 15min. Because sub-temperature quenching is heated in the α+γ two-phase zone, the quenching is performed in the state of local undissolved ferrite, maintaining high strength and toughness at the same time. improve.

The heat treatment of oil casing needs to be strictly implemented to ensure that the produced oil casing has good product quality and performance, exhibits good use value and performance in use, adheres to high strength and toughness, and conducts heat treatment in different ways.

At the same time, the low temperature quenching is lower than the conventional temperature, which reduces the stress of quenching, thereby reducing the deformation of quenching, which ensures the smooth operation of the production of oil casing heat treatment, and provides a good raw material for subsequent wire processing. .

At present, the process has been applied in different steel pipe processing plants. The quality assurance data shows that the tensile strength of the oil casing after heat treatment is Rm910-940MPa, the yield strength Rt0.6820-860MPa is 100% qualified, and the impact toughness is Akv65-85J data. It is indicated that K55 oil casing is already a relatively high-quality high-grade oil casing. On the other hand, it also shows that the sub-temperature quenching process is an effective method to avoid high temperature brittleness in the production of steel products.

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zora li
Joined: August 16th, 2022
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