441 steel grade is a new type of ultra-pure ferritic stainless steel developed in recent years. Its composition has the characteristics of ultra-low (C+N) and medium Cr, and a small amount of alloying elements Nb and Ti are added. The microstructure of 441 steel is characterized by single-phase ferrite, which has no organizational transformation during the process from high temperature to room temperature; in addition to good high temperature strength, corrosion resistance, weldability and processability, it also has good mechanical properties. Only Taiyuan Iron and Steel and Baosteel produce 441 steel in CHINA, and the rest rely on imports.
At present, 441 steel grades have been used in BMW automobiles, so they are more and more widely used in industrial production and daily life, such as exhaust manifolds, front pipes, CONVERTERs, heat exchangers, electronic components, etc. for automobile exhaust systems. Heat-resistant appliances, home appliances, tableware, gas stove tops, exterior decoration materials, etc. Since this kind of cold-rolled product is mainly used for its high temperature resistance, it is generally used in the exhaust pipe manifold and front pipe, so it is required to have excellent mechanical properties and surface quality .
