A kind of manufacturing method of 80ksi steel grade oil well pipe

Abstract

The invention provides a 80ksi steel grade oil well pipe and a manufacturing method thereof. The 80ksi steel grade oil well pipe comprises the following chemical components in percentage by weight: 0.15%-0.19% of C, 0.2%-0.3% of Si, 1.20%-1.40% of Mn, not greater than 0.015% of P, not greater than 0.003% of S, 0.6%-0.9% of Cr, 0.01%-0.03% of Nb, 0.04%-0.06% of Ti and 0.08%-0.12% of Cu; RE is steel of 50-90 g / t. The manufacturing method comprises the following steps: determining final rolling temperature at 1170-1190 DEG C by adopting a casting billet cold charge mode; determining the pipe manufacturing heating temperature at 1200-1240 DEG C, and determining the finish rolling temperature at 1020-1050 DEG C; keeping the quenching temperature at 820-840 DEG C for 20-25 minutes, carrying out water quenching, and keeping the tempering temperature at 665-675 DEG C for 25-35 minutes. The 80ksi steel grade oil well pipe provided by the invention is low in manufacturing cost, is enhanced in SSC (Sulfide Stress Corrosion Cracking) resistant property by 95% according to an NACETM 0177-2006 test without cracking of YSMIN within 720 hours, achieves the yield strength of 560-619 MPa, the tensile strength of more than 620 MPa and 0 DEG C V-shaped notch sample charpy impact energy of more than 100 J and is especially suitable for cold areas and ocean environments.

Description

technical field [0001] The invention belongs to the field of low-alloy steel pipe production technology, and in particular relates to a hydrogen sulfide corrosion-resistant oil well pipe with an 80ksi strength level and a manufacturing method thereof. Background technique [0002] In recent years, the massive exploitation of oil has forced many oilfields at home and abroad to adopt new oil recovery techniques such as secondary oil recovery and tertiary oil recovery water injection, which has brought about a new problem of hydrogen sulfide corrosion of oil well pipes with a strength level of 55-80ksi. In such a water environment, the oil well pipe is prone to sulfide stress corrosion cracking (SSC), so that the oil well pipe is damaged and the oil well is scrapped. The oil well pipe is required to have excellent hydrogen sulfide corrosion resistance and mechanical properties. From the perspective of oil well pipe materials, ordinary API oil well pipes obviously cannot meet th...

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Problems solved by technology

Therefore, the problem that this invention product exists is that cost is too high, and industrial implementation difficulty is big

[0007] The document Baosteel’s development and application of anti-corrosion series oil well pipes mentions Baosteel’s 80ksi steel grade hydrogen sulfide corrosion resistant oil well pipes, but it is only a general introduction, and the alloy design, manufacturing process and parameters of the products are not disclosed

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