High-pressure-resisting and low-carbon alloy steel material

Abstract

The invention provides a high-pressure-resisting and low-carbon alloy steel material. According to the low-carbon alloy steel material, except Fe element, the other elements by weight percent are as follows: 0.15-0.2% of C, 0.15-0.35% of Si, 0.7-0.9% of Mn, 0.001-0.015% of S, 0.001-0.015% of P, 0.45-0.65% of Cr, 0.7-1.0% of Ni, 0.45-0.6% of Mo, 0.02-0.05% of Al, 0.003-0.008% of V and 0.02-0.05% of Nb. A smelting technology combining electric furnace treating and vacuum refining degassing with electroslag re-smelting is adopted. The content of C element is properly reduced in the material; the trace elements Nb, V and Al are increased; the effects of increasing the strength by 15% and refining grains for 2-3 levels by the material are achieved; the ductility and the toughness of the material are further increased; the dosage of rare elements, such as Cr, Ni and Mo, is reduced; and the material belongs to a resource-saving type material.

Description

technical field [0001] The invention relates to the field of ferrous metals, in particular to a high-pressure-resistant low-carbon alloy steel material. Background technique [0002] High-pressure fluid delivery components (such as high-pressure swivel elbows) are important components used to deliver high-pressure fluids in oilfield operations such as drilling, cementing, fracturing, and testing. Because they deliver high-pressure fluids (pressures as high as 100 MPa or more) , but also to withstand the erosion of high-speed particles and the corrosion of acidizing fluid. The working conditions are extremely harsh, and fatigue cracks or stress corrosion cracks are prone to occur, resulting in the leakage of the fluid in the pipe and causing serious safety accidents. In order to ensure the safety of the product, the swivel elbow material is required to have high strength, good toughness and corrosion resistance, and must comply with API 6A or API 16C specifications. [0003]...

AI Technical Summary

Problems solved by technology

[0006] Due to the following defects, the above two materials are limited when used in high-voltage components such as 140MPa swivel elbows

One is that the cross section of the 140MPa swivel elbow is large, the hardenability of the raw material is insufficient, and the strength of the material after carburizing is not enough. The C content in the material 20CrNiMo and SAE8620 is high. Adverse effects; Second, due to the low Ni content of the material and the high C content, the grains of the material are coarse after carburizing at 930 ° C for a long time

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