A thin-gauge high-strength and toughness pipeline steel plate and its production method

Abstract

The invention discloses a thin high-flexibility pipeline steel plate and a production method thereof, belonging to the technical field of low-carbon microalloyed steel. The steel plate comprises the following chemical components in percentage by weight: 0.05-0.10 percent of C, 0.10-0.45 percent of Si, 1.35-1.85 percent of Mn, not more than 0.020 percent of P, not more than 0.005 percent of S, 0.01-0.05 percent of Alt, 0.03-0.06 percent of Nb, 0.03-0.06 percent of V, 0.01-0.02 percent of Ti, 0.00-0.20 percent of Mo and the balance of Fe and inevitable impurity elements. The production method is mainly characterized in that a low-temperature control rolling process is adopted for replacing an accelerated cooling process: the rolling temperature in a second stage is controlled to be 800-850 DEG C, the finish rolling temperature is controlled to be 660-720 DEG C, and room temperature is reached by adopting an air natural cooling manner after rolling. The production method has the advantages that the thin high-flexibility pipeline steel plate obtains better flexibility and better plate shape by adopting the low-temperature control rolling process instead of the accelerated cooling process under the condition of a reasonable component design, and solves the problems of performance and plate shape control of an intermediate-thickness plate of thin pipeline steel.

Description

technical field [0001] The invention belongs to the technical field of pipeline steel plate production, and in particular relates to a thin gauge high-strength pipeline steel plate and a production method thereof. This steel plate is produced by low-temperature controlled rolling instead of accelerated cooling process. The steel plate has excellent low-temperature toughness and good shape. Background technique [0002] As an economical, safe, and uninterrupted long-distance transportation tool for oil and natural gas, pipeline steel has achieved tremendous development in the past 70 years. Especially with the increase in energy demand, the grade and requirements of pipeline steel have continued to increase. At present, X60 and above grade pipeline steel mostly adopts low-carbon micro-alloy steel with controlled rolling and accelerated cooling rate. [0003] Due to the operation of the main pipeline of natural gas transmission under high pressure, the transmission pipeline n...

AI Technical Summary

Problems solved by technology

For high-grade pipeline steel, in order to ensure the strength and fracture toughness of the product, the production process of controlled rolling and accelerated cooling is often used, and the accelerated cooling process increases the difficulty of controlling the shape of the medium-thick plate, especially for thinner thickness specifications. For medium and thick plates with specific width and thickness specifications, it is extremely difficult to control the shape of the plate in winter months when the temperature is low. Therefore, it is necessary to propose a new production process to alleviate the problem of shape control of thin gauge high-strength and tough pipeline steel medium and heavy plates

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