Control method of cold heading steel flocculent flow

Abstract

The invention relates to the field of cold heading steel, in particular to a control method of a cold heading steel flocculent flow. The cold heading steel ML08AL comprises the following chemical components of, in percentage by mass, 0.06% to 0.09% of C, small than or equal to 0.08% of Si, 0.35% to 0.45% of Mn, small than or equal to 0.017% of P, small than or equal to 0.015% of S, 0.02% to 0.05%of Als, 0.03% to 0.05% of N, and the balance Fe. The production process comprises the following steps of preparing an iron mixer, pretreating molten iron, blowing a converter in a top-bottom combinedblowing manner, pre-deoxidizing molten steel, refining in an LF furnace and continuously casting square billets. During LF furnace refining, slag blocking and tapping are conducted, the thickness of slag in a steel ladle is controlled to be not larger than 50 mm, carbide slag and aluminum particles are mixed for deoxidation, the atmosphere in the LF furnace is controlled to be a reducing atmosphere, and argon bottom blowing and stirring are conducted. According to the method, the problem of cold upsetting cracking of the cold heading steel M108AL caused by many inclusions in the steel is solved, the non-metallic inclusions are graded, the grade is mainly 0.5 and 1.0, the grade 1.5 or above account for 5% or below of the total detected amount, the grain size reaches 8.5 or above, and the cold upsetting performance meets the requirement of 1 / 4.

Description

technical field [0001] The invention relates to the field of cold heading steel, in particular to a method for controlling floc flow of cold heading steel. Background technique [0002] Cold heading steel is to use the plasticity of metal to produce steel for standard parts with high interchangeability by cold heading forming process. Cold heading steel is often used for cold heading forming to manufacture various mechanical standard parts and fasteners, such as bolts, nuts, screws, rivets, self-tapping screws and other fasteners and various cold heading forming parts. Cold heading steel products are mainly used in industries such as automobiles, shipbuilding, equipment manufacturing, electronics, home appliances, bicycles, tools, light steel structures, and construction. The steel types of cold heading steel wire rod are generally low and medium carbon high-quality carbon structural steel and alloy structural steel. Due to the good cold forming performance of cold pier st...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a method for controlling the flocculation of cold heading steel, which solves the cold forging cracking problem of cold heading steel M108AL caused by many inclusions in the steel, and grades non-metallic inclusions with 0.5, 1.0 Grade 1.5 and above accounted for less than 5% of the total inspected, the grain size reached above 8.5 grade, and the cold upsetting performance met 1 / 4 of the requirements

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