Technical Study On Sandwich Rolling Of Low-alloy Wear-resistant Steel And Carbon Steel And Heat Treatment

With the progress of science and technology and the continuous development of emerging industries,people require higher and higher performance of the materials.The performance of a single material has been far from satisfying the needs of people,so now new composite materials research and development has become the mainstream of material research.In this topic experimental material was metal clad plate with NM450 D low-alloy wear-resistant steel as cladding and with Q235 B as base.We analyzed the microstructure and mechanical properties in the different processing plans-two-stage controlled rolling and off-line heat treatment to find the optimal parameters of off-line heat treatment process,and validate feasibility of this new processing plan for preparation of wear-resistant steel composite plate.In experiment,we made wear-resistant steel composite plate at different quenching temperatures,sub-critical quenching temperatures and temper temperatures respectively,and then used SEM and metallographic microscope to observe cladding and base layer of composite plate and the microstructure evolution of bonding interface,and meanwhile we determined interface bonding strength by mechanical properties test.Research results showed that,through the two-stage controlled rolling,cooling process after rolling the accurate grasp of each temperature parameter in off-line heat treatment process,each layer of microstructure of the wear-resistant steel composite plate we made was reasonable,and the bonding strength value and the hardness measured by mechanical properties test were have reached or exceeded national standard,fully testifying the feasibility of the process plan and research value.Meanwhile through the experiment,the off-line heat treatment can greatly improve the bonding strength of wear-resistant steel composite plate.The quenching temperature and temper temperature greatly impacted on microstructures and properties of the experimental steel;wear-resistant composite steel plate got through quenching at 900?and tempering at 250?,with a combination of hard and soft compound structure at the as base layer,with uniform and fine Martensite structure as cladding layer,achieved the best performance of the wear-resistant composite steel plate whether in the structure or its mechanical properties.Wear-resistant composite steel plate got through subcritical quenching at 820? was of good structure property,and ductility and toughness of the experimental steel was obviously improved without losing too much hardness,and the bonding strength also reached up to the use standard.