Packaging steel strip of banded structure is how to produce? How to eliminate?

Packaging steel strip of banded structure is how to produce? How to eliminate? After the banded structure refers to the structural steel hot working steel, ferrite and pearlite along the direction of the machining deformation cambium-like parallel alternating banded structure, formation of banded structure is caused by the improper composition segregation and hot working. In the process of casting the dendritic segregation will be made by the internal of impurities and alloying elements enrichment between branches, consequently higher phase transition point of the region. In hot working process, impurities and alloy element enrichment region along the machining deformation direction of the fiber distribution, processing after slow cooling rate, priority to fold the proeutectoid ferrite and carbon austenitic near to, are there changes into pearlite when carbon content increase. Proeutectoid ferrite along the impurities into separating out the fiber direction of alloy element was strips, formed in the sheet between ferrite and pearlite. Formed in the steel banded structure will cause lower transverse plasticity and toughness of steel, steel by machining performance, at the same time make the heat treatment deformation and hardness of the steel inhomogeneity increases, so should be eliminated. For the banded structure should use two normalizing treatment, high temperature normalizing (for the first time 900℃*2. 5 h, air cooling) , the purpose is to eliminate the banded structure, the second normalizing ( Air cooled) 860 ℃ * 2 h, , can refine grain, lower hardness, improve machinability, suitable for 40 cr, 40 MNVB, 45 MNB steel forging stock. In addition to improve the cooling rate after hot working, the forging repeatedly make the banded structure to reduce and eliminate.