Technical method for improving quality of high-strength cable steel casting blanks

Abstract

The invention discloses a technical method for improving the quality of high-strength cable steel casting blanks. The technical method comprises the steps that (1) the casting blanks enter a pit at the temperature of 550-680 DEG C to be slowly cooled, the blanks are stacked like a Chinese character 'jing', the blanks are subjected to capping cooling firstly at the cooling speed of 6-8 DEG C / h, andafter the temperature reaches 300 DEG C, the casting blanks are subjected to uncapping cooling to 200 DEG C or below and then taken out of the pit; (2) cogging is conducted, specifically, the castingblanks are heated and then rolled, and the initial rolling temperature is larger than or equal to 1100 DEG C; (3) shot blasting flaw detection is carried out, specifically, the shot diameter is 0.5-1.0 mm, and the shot blasting advancing speed of the casting blanks is 0.2-0.3 m / s; and (4) local coping is conducted, specifically, the coping modes include mechanical point coping and chamfer coping.According to the technical method, for the high-strength cable steel casting blanks, the temperature of pit entry for slow cooling and the cooling speed are controlled, and thus generation of abnormal structures, surface cracks and internal cracks of the casting blanks is effectively avoided; and by adoption of mechanical point coping and chamfer coping, the yield and the production efficiency are improved, and the comprehensive benefit is remarkable.

Description

technical field [0001] The application relates to the field of metallurgy technology, in particular to a process method for improving the quality of high-strength cable steel billets. Background technique [0002] Galvanized steel wire and steel strand for bridge cables are the core of modern large-scale bridges. With the development and progress of society, the span of bridges continues to increase. Correspondingly, the quality requirements for wire rods for galvanized steel wires for bridge cables are also getting higher and higher. There are strict requirements on surface quality and core quality. [0003] Due to the high carbon content and various alloying elements in cable steel blanks, segregation is difficult to control during smelting, and abnormal structures are prone to appear in the center of the wire rod after rolling, and the surface quality control of the blanks is unstable, prone to pits, indentations, Cracks, etc., will easily cause surface defects after rol...

AI Technical Summary

Problems solved by technology

[0004] In the prior art, the patent CN 109175322A discloses a slow cooling method for a large-section billet. The slow cooling in the pit reduces the occurrence of internal and external defects of the slab. This patent is mainly suitable for the slow cooling of carbon steel and alloy steel with a C content below 0.3%. The cooling speed control requirement during slow cooling has limited guidance for actual production; patent CN 106425759A adopts the method of full peeling and chamfering to clean the surface defects of spring steel; Surface quality, the patent CN 104141039A proposes to grind the billet to 2-4mm after billeting. The grinding methods mentioned in the above patents can eliminate the surface defects of the billet to a certain extent, but the amount of grinding is too large, and the yield Low, complex process, long grinding cycle, low production efficiency, and at the same time, no consideration is given to how to improve the uniformity of the internal structure of the billet and reduce the segregation of the billet, etc.

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