Production process for effectively preventing marine anchor chain round steel from generating cracks

Abstract

The invention relates to a production process for effectively preventing marine anchor chain round steel from generating cracks. A preparation method includes the steps of an electric furnace smelting procedure, a refining procedure outside an LF, a square billet continuous casting procedure and a rolling procedure. Chemical components are reasonably designed, the carbon equivalent is controlled, Ti microalloy reinforcement is added, the content of P and S is controlled to be smaller than or equal to 0.015%, the content of N is controlled to be smaller than or equal to 70 ppm, the content of residual elements of Cu, Nb and the like is reasonably controlled, the LF is well sealed, the soft blowing flow of argon is reasonably controlled, molten steel is prevented from absorbing nitrogen, aluminum deoxidation is enhanced, the soft blowing time of the argon is properly prolonged, whole-process protective casting is adopted for the continuous casting, the pulling speed and the superheat degree are low, proper protective slag is selected, the straightening temperature is raised, continuously cast billet enters a pit to be slowly cooled, the tapping interval is well controlled in a rolling manner, the compression ratio is increased, and a reasonable heat treatment process is selected. The marine anchor chain round steel produced through the method is simple in procedure and low in cost, vacuum treatment is not needed, and the technical problems that marine anchor chain round steel produced at present is bad in surface quality, high in crack occurrence ratio, not stable in quality and the like are solved.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and in particular relates to a production process for effectively avoiding cracks in ship anchor chain round steel. Background technique [0002] 85% of the world's trade is transported by ships, and marine anchor chains are indispensable and important components in ships and ocean engineering, and are high-strength and high-tech products. At present, China is one of the most important shipbuilding countries in the world, and export ships account for more than 70% of the country's total shipbuilding. With the development of ocean, river shipping and offshore oil mining industries, the anchor chain steel market has great potential and development prospects broad. Most of the marine anchor chain steels in industrially developed countries use grade III anchor chain steels with a tensile strength of 690MPa. Since grade III anchor chain steels are widely used in the mooring positioning of large sh...

AI Technical Summary

Problems solved by technology

[0004] If the user has cracks during use, the entire anchor chain may have to be scrapped, which will bring a heavy economic burden to the anchor chain manufacturer and greatly reduce the production efficiency of the enterprise. After being used for a period of time under corrosion and high-load conditions, corrosion and wear are serious, and cracks appear on individual links, which will also be complained by customers. How to obtain various performances and ideal surface quality that meet user requirements and avoid cracks, It is a common problem faced by domestic anchor chain steel manufacturers

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