A kind of oil casing steel grade and production process

Abstract

The invention discloses an oil casing steel grade, which is composed of the following components in terms of weight percentage: C: 0.28-0.36%, Si: 0.17-0.32%, Mn: 1.10-1.60%, P: ≤0.02%, S : ≤0.2%, Cu: ≤0.2%, Ni: ≤0.2%, Cr: ≤0.25%, Mo: ≤0.1%, V: ≤0.08%, Al: 0.008‑0.03%, other elements: ≤0.15%, remainder The amount is Fe, and the processing technology includes: converter smelting → refining outside the furnace → continuous casting round tube billet → hot-rolled seamless steel pipe → heat treatment → oil casing pipe body, the present invention specially adds 0.008 %‑0.030% Al can refine grains, improve the toughness of steel pipes, and meet API 5CT's requirement that the steel used for oil casing must be fine-grained killed steel; the steelmaking cost of this steel type is low, and the process control is easy. Cover the J55, M65, N80Q, L80‑1, R95, P110 multi-steel oil casings with a wide range of strength through appropriate processes, which can reduce the grades of steel used for oil casings, which is economical and practical. On the one hand, it facilitates the management of blanks And the organization of production, on the other hand, can reduce the stock blank and reduce the backlog of funds.

Description

technical field [0001] The invention belongs to the technical field of low-alloy steel, and in particular relates to an oil casing steel grade. Background technique [0002] Because of its large market demand and its specifications that are conducive to production, oil casings are favored by the majority of seamless steel pipe manufacturers. Domestically produced oil tubing and casings are mainly based on API SPEC 5CT "Casing and Oil Pipes" issued by the American Petroleum Institute. "Specification" is the standard. In the API 5CT 9th standard, all steel grades are H40, J55, K55, N80-1, N80-Q, R95, M65, L80-1, L80-9Cr, L80-13Cr, C90-1, For T95-1, C110, P110, Q125-1, for M65, N80Q, L80-1, R95, P110 steel grade oil casing pipe body, domestic manufacturers all use steel pipes of different materials to produce oil casing pipes of different steel grades, so On the one hand, it increases the burden on the management of billets, which is not good for the production organization. O...

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Problems solved by technology

[0002] Because of its large market demand and its specifications that are conducive to production, oil casings are favored by the majority of seamless steel pipe manufacturers. Domestically produced oil tubing and casings are mainly based on API SPEC 5CT "Casing and Oil Pipes" issued by the American Petroleum Institute. "Specification" is the standard. In the API 5CT 9th standard, all steel grades are H40, J55, K55, N80-1, N80-Q, R95, M65, L80-1, L80-9Cr, L80-13Cr, C90-1, For T95-1, C110, P110, Q125-1, for M65, N80Q, L80-1, R95, P110 steel grade oil casing pipe body, domestic manufacturers all use steel pipes of different materials to produce oil casing pipes of different steel grades, so On the one hand, it increases the burden on the management of billets, which is not good for the production organization. On the other hand, many companies add many alloying elements (such as Cr, Mo, V, etc.) to the quenched and tempered steel for production. Good, but its cost is too high, not conducive to market competition

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