Specification: hardness:52-62HRC useful life:can be produced more than 200000 cubic meter concrete or 300000 tons asphalt material:Hi-chrome standard: CN:KM TB Cr 15-25-GT US:ASTM A532 Class Two Type D strength of extension:380 N/mm2 extension at break:1% shock impact(resistance)value:>5 ak N.M/CM2 flexuralstrength:>600 ak N.M/CM2 certification:ISO9001:2008 application:concrete mixer production methods:casting In the fine grinding storehouse of small, medium or large-sized mills, manganese steel underboardings are being replaced by high-toughness martensitic steel ones. The high-toughness martensitic steel underboarding developed by our center is protracted in lifespan while its overhaul frequency is evidently decreased. Due to various work conditions of wet-grinding mill, the material selection varies as well. According to its work conditions, we have developed a kind of material suitable for wet-grinding, utilizing special heat treatment system to prolong the lifespan of its underboarding greatly.