A kind of hot-rolled low-alloy steel capable of reducing cracking caused by segregation and its production method

Abstract

Hot rolling low alloy steel capable of reducing cracking caused by segregation comprises, by weight, 0.12-0.18% of C, 0.005-0.04% of Si, 0.2-0.7% of Mn, not larger than 0.015% of P, not larger than 0.015% of S and 0.02-0.06% of Ti. The production method includes the steps of smelting, molten steel casting, casting blank heating, rough rolling, finish rolling and coiling. The argon blowing time is prolonged and the argon blowing intensity is increased after ferromanganese is added, the argon blowing intensity is increased from 5-10 m<3> / min to 10-20m<3> / min, and the argon blowing time is prolonged from original 5-10 min to not less than 15 min. The segregation in the steel is obviously lowered through the measures of control over the casting superheat degree, stable casting speed and the like, namely the banded structure is lowered. Therefore the cracking degree and phenomena are obviously lowered, and the yield is improved.

Description

technical field [0001] The invention relates to a hot-rolled steel plate and a production method, in particular to a hot-rolled low-alloy steel capable of reducing cracks caused by segregation and a production method. Background technique [0002] In recent years, with the expansion of steel consumption in the automobile and construction machinery industries, more low-alloy high-strength structural steels are used in cold forming fields that require bending and stamping. However, in the use of hot-rolled low-alloy commercial materials, it is mainly in the cold forming process such as bending and stamping. Due to the large amount of local deformation at the outer arc of the bending angle or the stamping edge, the cracking rate increases, and most of them are deep. , Nearly penetrating irreparable growing cracks. Cause can't satisfy user's requirement, and waste raw material and energy, cause production cost to increase. [0003] Aiming at this problem, the applicant has con...

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Problems solved by technology

[0004] After searching, there are literatures describing the method of controlling segregation of low-alloy steel, but only by reducing the content of P and S to reduce segregation, not by reducing the content of Mn, and not by adjusting Ti and other components and refining, slab heating, and rolling processes Systematic control of steel plate properties to reduce cold bending cracking

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