Thick-specification acid-corrosion-resisting X65 pipeline steel plate and manufacturing method thereof

Abstract

The invention discloses a thick-specification acid-corrosion-resisting X65 pipeline steel plate and a manufacturing method thereof. The yield strength of the steel plate is level 450MPa, a low-carbon and low-alloy composition design concept is adopted, the molten steel purity is improved through refining, the balled impurity form is processed through calcium, and production is performed through a controlled rolling and controlled cooling technology, so that the steel plate has the excellent HIC (hydrogen induced cracking) and SSCC (sulfide stress corrosion cracking) acid-corrosion resistance, and meanwhile, the steel plate is a product with excellent comprehensive properties such as the high strength, the high anti-crack toughness, the good weldability and the like.

Description

technical field [0001] The invention relates to a thick-gauge, high-toughness hydrogen-induced cracking-resistant (HIC) and H2S stress-corrosion-resistant (SSCC) X65 steel plate for pipelines, as well as a production method thereof, belonging to the technical field of pipeline steel manufacturing. Background technique [0002] With the increasing demand for natural gas clean energy in my country, the construction of natural gas pipelines is developing towards high strength, high toughness, large diameter, and high transmission efficiency. When transporting hydrogen sulfide (H 2 S) In case of natural gas in sour medium, in order to prevent the acid gas from corrosive damage to the pipeline, the pipeline steel is required to have resistance to hydrogen induced cracking (Hydrogen Induced Crack, HIC for short) and H 2 S stress corrosion (Sulfide Stress Corrosion, SSCC for short) performance. [0003] Natural gas resources are abundant in western my country, but H 2 The conten...

AI Technical Summary

Problems solved by technology

The material of this invention contains Ni element, and the cost is relatively high; in addition, [C] and carbon equivalent in the material are relatively high, which is unfavorable to the low-temperature toughness, formability, weldability, and ductility of the material, and affects the comprehensive performance after pipe making; the invention The maximum thickness of the material is 12mm, and the low-temperature drop weight tearing area value of the steel is not listed. For example, the high-pressure and high-density medium is transported, and its wall thickness and low-temperature crack arrest toughness are obviously insufficient. Great destructive power, poor security

[0005] In addition, the application number is 200510023651.3, titled "X65 pipeline steel for acidic environment and its manufacturing method" [patent comparison 2], which is the composition ratio and manufacturing method of X65 pipeline steel hot-rolled steel strip with HIC resistance, using low Carbon and high manganese composition design ideas, the carbon content is 0.02-0.05%, the converter sub-lance needs a large amount of oxygen blowing to achieve low carbon content, and the viscosity of the converter slag is very low, and the slag cannot be splashed to protect the furnace, which will greatly reduce the converter. life

The material in the invention only has HIC hydrogen-induced cracking resistance, and has not been tested for SSCC stress corrosion resistance. The stress corrosion resistance represents the material’s ability to resist hydrogen sulfide corrosion under dynamic loading force, which can better simulate the actual situation of pipelines transporting natural gas under pressure. Missing anti-SSCC check item

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