Thick-gauge hot continuous rolling steel belt with excellent ultralow temperature CTOD (Crack Tip Opening Displacement) performance and production method of thick-gauge hot continuous rolling steel belt

Abstract

The invention relates to the technical field of hot continuous rolling steel belts for use in submarine oil/gas transmission pipelines and provides a thick-gauge hot continuous rolling steel belt with excellent ultralow temperature CTOD (Crack Tip Opening Displacement) performance and a production method of the thick-gauge hot continuous rolling steel belt. According to the thick-gauge hot continuous rolling steel belt and the production method, the technical problem of high technical difficulty in the production of the thick-gauge hot continuous rolling steel belt with the excellent ultralow temperature CTOD performance in the prior art is solved. The production method comprises the following steps: (1) continuously casting a plate blank into a casting blank with the thickness of 230mm-240mm by virtue of 'complete pretreatment' smelting and LF refining; (2) carrying out offline detection on the casting blank; (3) putting the casting blank in a heating furnace, and heating, wherein the heating temperature is 1190-1230 DEG C, and the temperature equalizing time is more than or equal to 30 minutes; (4) carrying out a rough rolling process; (5) carrying out a precision rolling process, wherein the thickness of the rolled steel belt is 16mm-20.2mm; (6) carrying out a laminar flow cooling process; and (7) reeling at the temperature of 480-560 DEG C. The production method can be used for producing the thick-gauge hot continuous rolling steel belt with the excellent ultralow temperature CTOD at relatively low difficulties.

Description

technical field [0001] The invention relates to the technical field of hot-rolled steel strips for submarine oil / gas pipelines, in particular to a production method of thick-gauge hot-rolled steel strips with excellent ultra-low temperature CTOD performance. Background technique [0002] In the past 10 years, more than 50% of China's new oil production has come from the ocean, and offshore oil and gas development is in the key areas, and the demand for steel for submarine pipelines is also increasing. Due to the harsh service environment, the steel used for submarine pipelines has stricter requirements than the steel used for buried gas pipelines. In addition to the general implementation of DNV (DET NORSKE VERITAS: Det Norske Veritas) standards, the designer will put forward more stringent requirements. Security is guaranteed. For example, steel for submarine pipelines requires high weldability and low carbon equivalent. X65 grade requires carbon equivalent CE≤0.39, and us...

AI Technical Summary

Problems solved by technology

[0007] The invention provides a thick-gauge hot-rolled steel strip with excellent ultra-low temperature CTOD performance and a production method to solve the technical problem of high technical difficulty in producing a thick-gauge hot-rolled steel strip with excellent ultra-low temperature CTOD performance in the prior art

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