430 Ferritic Stainless Steel Production Process
Among the ferritic stainless steels, 430 ferritic stainless steel is used and produced the most, second only to 304 austenitic stainless steel in some countries. The main advantages of 430 ferritic stainless steel are low price and low thermal expansion coefficient. Chloride stress corrosion resistance is better than 300 series stainless steel springs. Especially after adding trace elements niobium, titanium, copper, aluminum, etc., the deep drawing performance, welding performance, corrosion resistance, antibacterial resistance and high temperature strength of ferritic stainless steel have been improved to varying degrees, making ferritic stainless steel springs Have a foundation for a wide range of applications.
430 ferritic stainless steel cold-rolled strip steel is widely used in deep drawing applications such as kitchen equipment, utensils, and home appliances. Therefore, the cold forming performance of this type of ferritic stainless steel is very important. In addition to the influence of chemical composition on cold forming performance, the production process also has an important influence on cold forming performance.
In the production process of ferritic stainless steel, in order to meet the requirements of final cold rolling, a key and expensive process is annealing after hot rolling. The traditional process route is that the hot-rolled strip steel must be annealed in a bell furnace. The entire annealing cycle is long and energy consumption is very high.
In order to reduce energy consumption, reduce production costs, improve product competitiveness, and at the same time meet the final cold-rolled requirements for hot-rolled strip steel, ThyssenKrupp AST of Germany produces ferritic stainless steel in large quantities according to its own, of which about 20 % Is the characteristic of 430 ferritic stainless steel. After years of research and testing, a new process has been developed that consumes less energy, is shorter in time than the bell furnace annealing process, is cost-competitive and can fully meet the final cold rolling requirements , The direct annealing process. The basic principle of this process is to use the waste heat after hot rolling to immediately perform annealing treatment.
This article describes in detail the equipment used by the direct annealing process and the advantages of the process (small heat loss of hot-rolled steel coils, low power consumption, short cycle time, reduced production costs by about 60%, and all properties of rolled materials fully meet the requirements.