Production process for eliminating boron micro-alloying hot-rolled steel strip edge faults

Abstract

A production process for eliminating boron micro-alloying hot-rolled steel strip edge faults is characterized by meeting key control conditions that when content of [B] in steel is smaller than 0.0013%, content of [Mn] is larger than or equal to 0.35% while content of [S] is smaller than or equal to 0.005%; when content of [B] in steel is larger than or equal to 0.0013% and smaller than or equal to 0.0020%, content of [Mn] is larger than or equal to 0.40% while content of [S] is smaller than or equal to 0.005%; the content of molten steel N of continuous casting tundish is controlled to be smaller than or equal to 60ppm; the corner temperature of continuous casting billets in a straightening area of a segment is over 1000 DEG C so that a brittleness temperature range of 850-950 DEG C is avoided; the content of molten steel P is controlled to be smaller than or equal to 0.015% while the content of C is out of the range of 0.09-0.17%. By the production process, control target is clear, operations can be realized easily and conveniently, corner transverse cracks caused by boron micro-alloying of the continuous casting billets can be eliminated completely, manual operations of checking and cleaning the corner faults of the billets are omitted, qualified steel strip products can be rolled directly, production processes are simplified, energy consumption is reduced, labor intensity of workers is lowered, and product quality is stable and reliable.

Description

technical field [0001] The invention relates to the field of metallurgy and steelmaking, in particular to a production method for eliminating edge defects of boron microalloyed hot-rolled steel strips. Background technique [0002] When producing boron (B) microalloyed (B content 0.0003% to 0.0020%) hot-rolled steel strips, defects such as edge cracks and heavy skins of the hot-rolled steel strips often occur. Department of transverse cracks. According to the current conventional production method, it is difficult to completely eliminate the transverse cracks at the corners of the continuous casting slab during the production process. After the continuous casting slab is cooled, it needs to be inspected and ground to clean the transverse cracks at the corners. Even so, edge defects of the hot-rolled steel strip still occur , Product quality cannot be guaranteed to be stable. The main reason for the edge defects of this steel strip is the addition of boron, and the specific...

AI Technical Summary

Problems solved by technology

[0006] 4. The intergranular cracks of the continuous casting slab are easy to form transverse cracks at the weak vibration marks at the corners of the slab, and these corner transverse cracks will eventually develop into side defects such as edge cracks and heavy skins during the hot rolling process