A few days ago, JISCO made a new breakthrough in the production process of 65Mn medium and high carbon steel. The product has a 180-degree bending“Soft strength” while achieving the perfect welding of steel“Hard touching hard”. This technology is a new way for JISCO to expand the application of medium and high carbon steel products, improve the added value of products and promote the enterprise to play a positive role in“Quality improvement and efficiency improvement, transformation and upgrading.”.
“The tensile strength of 65MN cold-rolled medium-high carbon steel reaches 580MPA, which means it meets the requirements of the national standard. But the market customers according to personalized processing needs, the product’s performance put forward higher requirements, the product must be able to bend and stretch to achieve 180-degree bending without breaking. This also forces enterprises to continuously increase technological innovation and enhance product value-added,” said Di Yanjun, product R & D engineer at Hongxing carbon steel plate and belt research institute.
In order to meet the company’s profit maximization, JISCO has to produce medium and high carbon steel at the lowest production cost and also achieve special performance requirements such as 180-degree bending, which is a great challenge to the existing production process and technology. In order to meet the requirements of the next cold rolling process, secondary annealing is usually used to reduce the strength of hot rolled medium and high carbon steel in domestic steel enterprises. During the recent rolling of 65Mn medium and high carbon steel, JISCO has decided to change the secondary annealing process in the same industry, and to improve the plasticity of the intermediate product by adjusting the controlled rolling and controlled cooling parameters many times, the continuous production process of flash welding + pickling cold continuous rolling is adopted to realize the low-cost production mode of one-time annealing. Finally, the 65Mn medium and high carbon steel reach 930MPA after hot rolling and 580MPa after cold rolling and annealing, and the carbon equivalent of the steel reaches 0.8%, which is far beyond the equipment limit of 0.5% in acid rolling flash welding design.
In order to ensure the smooth rolling of high-performance 65Mn medium and high carbon steel, the carbon steel sheet plant decided to challenge the limit of production equipment. At the same time, the“Hard impact” welding and rolling of medium and high carbon steel is realized for the first time without the connection of middle and low strength steel. Through unremitting efforts, the carbon steel sheet mill in mid-December 2020 successfully rolled to meet customer orders of high-performance products, after testing, products can meet the 180-degree bending performance requirements.
In the market, medium and high carbon steel have a wide range of applications because of its high strength and good wear resistance. It can be used in the fields of auto parts, special equipment, and cutting tools. The 65Mn medium and high carbon steel products developed by JISCO not only have good wear resistance but also can achieve the requirements of 180-degree bending without cracking, etc. . For winning more market orders, it has played a positive role in promoting enterprise innovation and innovation.