Wear-resistant cladding plates consisting of a substrate（Q345 R） and a clad layer（BTW1） were bonded through hot rolling at the temperature of 1 200 ℃ and a rolling speed of 0.5 m/s. The microhardness of the cladd...Wear-resistant cladding plates consisting of a substrate（Q345 R） and a clad layer（BTW1） were bonded through hot rolling at the temperature of 1 200 ℃ and a rolling speed of 0.5 m/s. The microhardness of the cladding plate was also tested after being heat treated. The microstructure evolution on the interface of BTW1/Q345 R sheets under various reduction rates was investigated with a scanning electron microscope（SEM） and EBSD. It is found that the micro-cracks and oxide films on the interface disappear when the reduction is 80%, whereas the maximum uniform diffusion distance reaches 10 μm. As a result, a wide range of metallurgical bonding layers forms, which indicates an improved combination between the BTW1 and the Q345 R. Additionally, it is discovered that the unbroken oxide films on the interface are composed of Mn, Si or Cr at the reductions of 50% and 65%. The SEM fractography of tensile specimen demonstrates that the BTW1 has significant dimple characteristics and possesses lower-sized dimples with the increment in reduction, suggesting that the toughness and bonding strength of the cladding plates would be improved by the increase of reduction. The results reveal that a high rolling reduction causes the interfacial oxide film broken and further forms a higher-sized composite metallurgical bonding interface. The peak microhardness is achieved near the interface.展开更多
Only a few studies have been conducted on the flow behavior of the novel BTW1/Q345R bimetal,which is widely used in coal equipment.In this work,compression tests were conducted on BTW1/Q345R bimetal at a temperature r...Only a few studies have been conducted on the flow behavior of the novel BTW1/Q345R bimetal,which is widely used in coal equipment.In this work,compression tests were conducted on BTW1/Q345R bimetal at a temperature range of 950°C–1200°C and strain rates of 0.05,0.5,5,and 15 s^−1 by using a Gleeble-3800 thermomechanical simulator.A constitutive equation was validated by referring to the Arrhenius equation during the characterization of hot workability.The computed apparent activation energy of the BTW1/Q345R bimetal was 360 kJ/mol,and processing maps under different strain conditions were drawn.Analysis of the stress-strain relationship revealed that work hardening exerted a dominant effect on the thermal deformation of the BTW1/Q345R bimetal.The processing maps predicted that the optimal processing interval will increase with strain.Results showed that thermal deformation of the BTW1/Q345R bimetal should proceed when the temperature range varies from 1182°C to 1200°C and the strain rate interval is from 4.2 to 15 s^−1.展开更多
基金the National Natural Science Foundation of China(No.U151013)the Key Research and Development Program of Shanxi Province(Nos.201603D111004 and 201603D121010)+1 种基金the Natural Science Foundation of Shanxi Province of Chinathe Provincial Special Fund for Coordinative Innovation Center of Taiyuan Heavy Machinery Equipmen(No.20171003)
文摘Wear-resistant cladding plates consisting of a substrate（Q345 R） and a clad layer（BTW1） were bonded through hot rolling at the temperature of 1 200 ℃ and a rolling speed of 0.5 m/s. The microhardness of the cladding plate was also tested after being heat treated. The microstructure evolution on the interface of BTW1/Q345 R sheets under various reduction rates was investigated with a scanning electron microscope（SEM） and EBSD. It is found that the micro-cracks and oxide films on the interface disappear when the reduction is 80%, whereas the maximum uniform diffusion distance reaches 10 μm. As a result, a wide range of metallurgical bonding layers forms, which indicates an improved combination between the BTW1 and the Q345 R. Additionally, it is discovered that the unbroken oxide films on the interface are composed of Mn, Si or Cr at the reductions of 50% and 65%. The SEM fractography of tensile specimen demonstrates that the BTW1 has significant dimple characteristics and possesses lower-sized dimples with the increment in reduction, suggesting that the toughness and bonding strength of the cladding plates would be improved by the increase of reduction. The results reveal that a high rolling reduction causes the interfacial oxide film broken and further forms a higher-sized composite metallurgical bonding interface. The peak microhardness is achieved near the interface.
基金This work was supported by the Applied Basic Research Project of Shanxi Province,China(Grant Nos.201701D121078 and 201701D221143)the National Natural Science Foundation of China(Grant No.U1510131).
文摘Only a few studies have been conducted on the flow behavior of the novel BTW1/Q345R bimetal,which is widely used in coal equipment.In this work,compression tests were conducted on BTW1/Q345R bimetal at a temperature range of 950°C–1200°C and strain rates of 0.05,0.5,5,and 15 s^−1 by using a Gleeble-3800 thermomechanical simulator.A constitutive equation was validated by referring to the Arrhenius equation during the characterization of hot workability.The computed apparent activation energy of the BTW1/Q345R bimetal was 360 kJ/mol,and processing maps under different strain conditions were drawn.Analysis of the stress-strain relationship revealed that work hardening exerted a dominant effect on the thermal deformation of the BTW1/Q345R bimetal.The processing maps predicted that the optimal processing interval will increase with strain.Results showed that thermal deformation of the BTW1/Q345R bimetal should proceed when the temperature range varies from 1182°C to 1200°C and the strain rate interval is from 4.2 to 15 s^−1.
