Seamless steel tube for petroleum cracking and heat treatment method thereof

Abstract

The invention provides a seamless steel tube for petroleum cracking. The steel tube comprises the following components in percentage by weight: 0.08 to 0.15 percent of C, 0.20 to 0.50 percent of Si, 0.30 to 0.60 percent of Mn, less than or equal to 0.020 percent of P, less than or equal to 0.020 percent of S, less than or equal to 0.20 percent of Ni, 4.00 to 6.00 percent of Cr, 0.40 to 0.55 percent of Mo, less than or equal to 0.20 percent of Cu, less than or equal to 0.015 percent of Al, less than or equal to 0.08 percent of V, less than or equal to 0.01 percent of Nb, less than or equal to 0.008 percent of N, and the balance of Fe. The invention also provides a normalizing and tempering heat treatment process for producing the seamless steel tube. The invention has the advantages that: the steel tube is subjected to heat treatment by strictly controlling chemical compositions and adopting a heat treatment system beyond a GB9948 standard, various properties of the steel tube which issubjected to heat treatment meet the requirements of the standard, and the steel tube can be used for high-temperature furnace tubes and components for petroleum cracking.

Description

technical field [0001] The invention relates to a seamless steel pipe, in particular to a seamless steel pipe for petroleum cracking and a heat treatment method thereof. Background technique [0002] As the rapid development of science and technology has brought negative impacts such as environmental pollution, people have gradually realized this serious problem and began to invest a lot of energy and financial resources in environmental improvement. The seamless steel pipes used for high-temperature furnace pipes and components of petroleum cracking require high corrosion resistance and certain high-temperature strength, but at the same time, it is also required that the strength and hardness at room temperature should not be too high, and at the same time, the impact toughness should be high, so as to meet the processing performance and security of operation. [0003] In response to this performance requirement, GB9946 proposes an annealing heat treatment process for 1Cr5...

AI Technical Summary

Problems solved by technology

However, the annealing heat treatment process needs to heat the steel pipe for a long time, the production cycle is long, and the production efficiency is low. This process is not suitable for continuous heat treatment furnaces.

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