Steel for long-service-life fracturing pump valve body suitable for unconventional oil and gas operation and forging method thereof

Abstract

The invention discloses steel for long-service-life fracturing pump valve body suitable for unconventional oil and gas operation, and belongs to the field of alloy steel. The steel for the fracturing pump valve body comprises, by weight, 0.30%-0.45% of C, 0.15%-0.35% of Si, 1.5%-2.5% of Mn, 0.8%-1.0% of Cr, 0.6%-0.8% of Mo, 2.00%-2.50% of Ni, 0.05%-0.25% of V, 0.015%-0.040% of Al, 0.01%-0.03% of Sb, less than or equal to 0.015% of P, less than or equal to 0.015% of S, less than or equal to 0.0080% of N, less than or equal to 0.004% of O, and the balance Fe and other inevitable impurities. The proportions of the elements should meet the following conditions: (1) 0.20% < =% C -(0.077 *% Cr + 0.24 *% V) < = 0.32%; 2) 4 *% Ni + 1.2 *% Cr-1. 5 *% Si + 17 *% Sb + 10 *% V-9 *% Ni *% Sb-5 *% Mn > = 1.0. According to the fracturing pump valve body prepared from the steel, the tensile strength at the one fourth thickness position is larger than or equal to 1050 MPa, the yield strength is larger than or equal to 900 MPa, and KV2 at minus 27 DEG C is larger than or equal to 100 J, under the action of 140MPa stress, in a fracturing fluid environment, the stress corrosion fatigue life is more than or equal to 3.5 million times, and the requirement that a fracturing pump serves for 350h is met.

Description

Technical field [0001] The present invention belongs to the field of alloy steel, and more particularly to tensile strength ≥ 1050 MPa, yield strength ≥900MPa, -27 ° C kV 2 ≥100J, a very good oil and gas operating fracturing pump valve body steel and forged work artificial art. Background technique [0002] With the deterioration of the oil and gas drill, 90% of the oil and gas wells need to be fracturing operations to increase recovery. The fracturing pump is an important equipment for fracturing, acidification operation, embrace formation, improving oil and gas production and reduced reserves. As my country's oil and gas reserves are gradually reduced, oil, gas well exploitation is increasing, in order to improve mining efficiency, increase oil and gas production, fracturing parameters (pressure, speed, etc.) have also increased year by year. [0003] The fracturing pump valve body has a harsh working environment, and it is often invalid in a comparative environment in high-pre...

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Problems solved by technology

[0004] The prior art with Chinese patent publication number CN112501507A discloses a high-strength alloy structural steel for fracturing pump cylinders and its preparation method, in order to solve the cracking failure and fatigue damage of the above-mentioned materials in fracturing operation equipment The problem is to provide high-strength alloy structural steel for fracturing pump cylinders. The technical proposal is as follows: the chemical element composition of the steel and the weight percentage of each component are: C 0.300.36, Mn0.230.28, P≤0.015, S ≤0.010, Si0.050.10, Ni 3.203.30; Cr 1.401.50; Mo 0.550.60, V 0.110.15, H≤1.5ppm, O≤112ppm, N≤70120ppm, others are Fe

[0006] At present, the commonly used materials for pressure pump valve bodies in the world are 4130 and 4330. In my country, there are 30CrNi2MoA, 35CrNi2MoA, 40CrNi2MoA, etc., but they all face the problem of short service life.

Some enterprises use stainless steel 15-5 and 17-4 to manufacture fracturing pump valve bodies. Although they can improve the service life, they face the problems of high cost and difficult forming

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