The grooves of Large-sized section mill rolls are normally deep; whilst rolling steels, due to the contact with the high temperature rolling piece, impact, rolling force, thermal force, as well as affected by cooling water, rolls need to have strong performance.
On the contrary, it will affect rolling efficiency and steel surface quality.
Today we’re gonna talk about Hot Working Die (HWD) rolls mechanical properties:
- Thanks to the optimized composition of HWD rolls, especially by adding right amount of special hard-to-be-fused alloy elements, which enables carbides form the discontinuity and binary structure, through its type, qty, size, form, distribution, so as to improve the tensile strength, impact strength of toll steel rolls, thus extending roll campaign.
- By innovation of roll process, forging can be replaced by casting; max tensile strength can be more than 1320MPa, which is better than forged rolls. It can be used on BD1 stand of section roughing mills, also applied to R1 stands of strip roughing mills, large bar roughing stands.
- The great performance of HWD rolls, mainly reflects on its structure: tempered sorbites + small amount of residual austenites + ferrites. Barrel hardness can be up to 50-65 HSD