Recently, Henan Steel Group achieved a major technological breakthrough in the production of continuous casting high manganese non-magnetic steel. For the first time in China, a 3250 mm wide and thin arc casting machine was used to successfully complete the stable and continuous casting of 20Mn23AlV products. The width-to-thickness ratio of the slab exceeded 13, and multiple specifications of steel plates were rolled out in one go. The first batch of continuous casting high manganese non-magnetic steel 20Mn23AlV products has been successfully delivered, and the surface quality and various performance indicators of the products meet the customer's requirements. This move fills the technological gap in the domestic production of this steel grade by wide slab continuous casting and opens up a new path for the large-scale production of high alloy special steel.
Continuously cast high-manganese non-magnetic steel is a demonstrative material listed in the "First Batch of Key New Materials Application Demonstration Guidance Catalogue (2024 Edition)" issued by the Ministry of Industry and Information Technology, and belongs to the high-end special steels that are key areas of national support and promotion. This steel is a key core material in the field of power equipment, possessing ultra-low magnetic permeability, high strength, high toughness, and excellent processing performance. It can effectively reduce magnetic leakage losses in power equipment, significantly improve power operation efficiency and safety stability, and is widely used in the manufacture of high-end power equipment such as magnetic shielding for large transformers and non-magnetic structural components for generators, as well as in power transformers, precision electronic instruments, and aerospace fields.
This steel grade has a high manganese and aluminum alloy content, making production control difficult and prone to quality defects such as billet cracks and uneven composition. The entire process of smelting, continuous casting, and rolling has significant technical barriers. In particular, the continuous casting of wide and thin slabs has extremely high requirements for equipment and process matching, and is prone to problems such as steel leakage and large fluctuations in the liquid level of the crystallizer. Previously, there was no successful precedent for the industrialized production of wide slab continuous casting in China.
Leveraging its advanced equipment, the Henan Steel technical team formed a special task force to systematically tackle the technical challenges of continuously casting high-manganese non-magnetic steel. During the casting process, the team precisely designed and optimized key process parameters, overcoming core technical bottlenecks such as continuous casting, protective slag, and cooling regime. They successfully solved several common industry problems related to this steel grade, including fluctuations in the continuous casting process and low billet qualification rates.