High strength resistance welding casing pipe and manufacturing method thereof

Abstract

The invention provides a high strength resistance welding casing pipe and a manufacturing method thereof. The casing pipe is prepared from the following components in percentage by weight: 0.25 to 0.30 percent of C, 0.10 to 0.30 percent of Si, 1.25 to 1.60 percent of Mn, smaller than or equal to 0.020 percent of P, smaller than or equal to 0.008 percent of S, 0.05 to 0.20 percent of Mo, 0.05 to 0.15 percent of Cu, 0.010 to 0.030 percent of Ti, 0.02 to 0.05 percent of Als, smaller than or equal to 0.008 percent of N and the balance of Fe and inevitable elements; in addition, Ceq is smaller thanor equal to 0.55, Ceq is equal to the ratio of C plus Mn to 6 plus (Cr+Mo+V) to 5 plus (Ni+Cu) to 15. The manufacturing method comprises smelting, continuous casting, continuous-casting billet reheating, rolling, cooling, coiling, ERW tabulating and whole tube heat treatment; the final organization of a steel pipe produced by the invention is tempered sorbite and the performance is P110 level, sothat the consistency of a pipe body and welding performance is ensured.

Description

technical field [0001] The invention belongs to the field of metal materials, in particular to a straight seam resistance welding sleeve and a manufacturing method thereof. Background technique [0002] Oil casing is one of the most commonly used petroleum-specific pipes in oil fields. It consumes a lot of money and costs a lot. It is an indispensable construction material in oil and gas field drilling operations. Compared with seamless pipes, HFW casings have significant advantages such as uniform wall thickness, high dimensional accuracy, good perforation performance, strong collapse resistance, and low cost, and are gradually replacing traditional seamless steel pipes. [0003] At present, the development of many oilfields in my country has entered the middle and later stages, and the development difficulty is becoming more and more difficult. In particular, deep wells put forward higher requirements on the mechanical properties of casings, and at the same time require ce...

AI Technical Summary

Problems solved by technology

[0015] Aiming at the technical problems existing in the current production of straight seam resistance welded petroleum casing P110, for example: the common addition of alloy Cr will easily cause microscopic component segregation and cause microcracks near the weld; the strength of the hot-rolled state reaches P110, and it is difficult to make pipes with high strength etc., the technical solution of the present invention is proposed, and the composition design adopts low Mo and Cr-free design

Images