Preparation of Q235/CrWMn cutting tool material by composite casting and hot rolling

A composite cutting tool material,consisting of Q235 and CrWMn steel,was prepared by composite casting and hot rolling process.Through vacuum melting and casting,followed by hot rolling deformation with a relative reduction larger than 90%,excellent metallurgical bonding between the component materials was obtained,with an interface layer of only 10 to 40 μm wide.Heat treatment experiments with different cooling modes were carried out.The results showed that after air cooling or oil quenching,a mixture microstructure of ferrite and pearlite in Q235 was formed.While in the side of CrWMn,a martensite structure with a micro hardness of 600 to 750 HV was found.The composite material exhibits the excellent comprehensive mechanical properties of both high toughness and strength.