What are rolls? What is the main material? What are they used for?
The roll is an important part of the rolling mill in a steel rolling mill, using a pair or group of rolls to roll the pressure generated when rolling steel. It is mainly subjected to rolling dynamic and static loads, wear and temperature changes.
The rolls are divided into hot rolls and cold rolls of two kinds.
Commonly used cold rolls in the work roll materials are 9Cr, 9Cr2, 9Crv, 8CrMoV, etc. Cold rolls require surface quenching, hardness HS45 ~ 105.
The materials commonly used for hot rolls are 55Mn2,55Cr,60CrMnMo,60SiMnMo etc. Hot rolls are used in the processing of open billets, thick plates and sections. It is subjected to strong rolling forces, severe wear and thermal fatigue, and hot rolls work at high temperatures and allow for diameter wear per unit of workload, so surface hardness is not required, only high strength, toughness and heat resistance. Hot rolls are only normalised or quenched as a whole, with surface hardness requirements of HB190~270.