High-strength toughness steel for continuous sucker rod and method for manufacturing same

Abstract

The invention discloses steel with high strength and toughness applied in a coiled rod and a manufacturing method thereof, solving the problems of the existing coiled rods that the strength and the plasticity are low and not well matched, and fatigue crack occurs frequently. The manufacturing method comprises the following steps: 1) the chemical components of the steel by weight percentage are: 0.12-0.22 percent of C, 0.15-0.40 percent of Si, 0.30-0.60 percent of Mn, 0.20-0.40 percent of Mo, 1.30-1.95 percent of Ni, 0.40-0.60 percent of Cr, 0.20-0.35 percent of V, 0.015-0.050 percent of Al, less than or equal to 0.30 percent of Cu, less than or equal to 0.0 15 percent of S, less than or equal to 0.020 percent of P and the rest of Fe; 2) smelting, ladle refining and continuous casting to form blocker: the (O) is less than or equal to 0.0025 percent and the (H) is less than or equal to 0.00015 percent; 3) casting blank and heating: the soaking temperature is 1130-1180 DEG C, heat preservation is more than or equal to 2.5 h, and the tapping temperature is 1100-1180 DEG C; 4) control of rolling: the temperature of finishing rolling is 820-860 DEG C; 5) control of cooling: the cooling speed is 40-80 DEG C per hour. The steel of the invention improves the comprehensive mechanical performances and fatigue life of the coiled rod and fulfils the development of the petroleum industry.

Description

technical field [0001] The invention relates to the composition design and manufacturing method of structural steel in the metallurgical industry, in particular to the composition design and manufacturing method of high-strength and high-toughness continuous sucker rod steel. Background technique [0002] At present, more than 90% of oil wells on land in my country use rod pumps for oil production. Steel sucker rods are generally used, which can be divided into D-grade rods and H-grade rods according to their strength levels. The steel grades used for D-grade rods are 35Mn2, 35CrMo, and 42CrMo. The H-grade rods mainly include 12Mn2SiCr, 16Mn2SiCr, and 20Cr2MoNi. Wait. The D-grade sucker rods recommended by the American Petroleum Institute are: 1536 and 4142 (equivalent to 35Mn2 and 42CrMo steel respectively). With the rapid development of the oil production industry and many oil fields are in the late stage of production, the oil production layer is gradually lowered and t...

AI Technical Summary

Problems solved by technology

[0013] The purpose of the present invention is to provide a high-strength toughness continuous sucker rod steel and its manufacturing method, to solve the existing sucker rod strength, low plasticity and poor matching between strong and plastic, prone to fatigue fracture problems; improve the sucker rod steel Comprehensive mechanical properties, improve the fatigue life of the sucker rod, improve the overall stability of the pumping equipment, and further meet the development of the petroleum industry