Production method of low-temperature high-strength high-toughness steel for lifting rings

Abstract

The invention relates to the field of production technologies of lifting rings and in particular relates to a production method of low-temperature high-strength high-toughness steel for lifting rings. The production method comprises the following steps: electric-arc furnace smelting, vacuum refining, electroslag remelting, heating, forging and heat treating process after forging. A raw material adopted by the production method is Cr2Ni4 high-alloy steel, Mo and V alloy elements are added, and the proportions of the components are controlled as follows: C is 0.18-0.23%, Si is 0.20-0.50%, Mn is 0.30-0.60%, Ni is 3.25-3.65%, Cr is 1.25-1.65% Mo is 0.05-0.20%, V is 0.02-0.10%, S is less than or equal to 0.015%, and P is less than or equal to 0.025%. The forging mode is oil press square pulling forging, and normalizing is carried out by utilizing forging waste heat after forging. The low-temperature high-strength high-toughness steel for lifting rings, which is provided by the invention is used at a low temperature and can improve the safety and the reliability.

Description

technical field [0001] The invention relates to the technical field of suspension ring production, in particular to a production method of low-temperature high-strength and high-toughness steel for suspension rings. Background technique [0002] With the rapid development of the global economy and the continuous shortage of energy sources, the price of oil at home and abroad has soared and the demand for oil has continued to rise. The shortage of oil is imminent. In order to explore more oil, the oil drilling and production industry has turned their attention to extremely low temperature, desert, sea, swamp, mountain and other harsh environments, which put forward higher requirements for oil drilling and production equipment, especially the stress on the drilling rig lifting system. The key part of the drilling machine is the lifting ring. The performance, safety and reliability of the lifting ring are directly related to the use of drilling equipment. [0003] At present, ...

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Problems solved by technology

[0003] At present, due to unreasonable design of suspension ring material composition and poor forging compaction technology, the properties of commonly used suspension ring materials at home and abroad are extremely unstable, especially the yield strength and low temperature impact toughness cannot meet Rp0.2≥1180MPa, Akv (-20 ℃) ≥ 42J, Akv (-45 ℃) ≥ 27J requirements, making it difficult to meet the requirements of the safety factor of drilling rig equipment between 2.75 and 3.0, which ultimately affects the safety and reliability of drilling rig equipment used under low temperature conditions

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