After different heat treatment processes, the metal compound, the microstructure and the hardness of the C-Cr-W- Mo-V-RE Fe-based hardfacing layers are investigated by means of metallographic microscope, X-ray diffrac...After different heat treatment processes, the metal compound, the microstructure and the hardness of the C-Cr-W- Mo-V-RE Fe-based hardfacing layers are investigated by means of metallographic microscope, X-ray diffraction （ XRD ）, energy dispersive spectrum（ EDS ）, transmission electron microscope（TEM） and hardness tester. The results show that the hardfacing layers have higher tempering stability and secondary hardening property. After quenching at 820 ℃ ,the hardness value（ HRC37 ） and the microstructure of the layers are similar to that normalized at 820 - 1 000 ℃. The tempering stability and the hardness increases with increasing quench temperature, which is attributed to the amount of the alloy element in the matrix. These results are very helpful for improving the mechanical properties of the hardfacing layers.展开更多
The changes of tempering microstructure and properties of Fe-Cr-V-Ni-Mn-C cast alloys with martensite matrix and much retained austenite are studied. The results showed that when tempering at 200 °C the amount of...The changes of tempering microstructure and properties of Fe-Cr-V-Ni-Mn-C cast alloys with martensite matrix and much retained austenite are studied. The results showed that when tempering at 200 °C the amount of retained austenite in the alloys is so much that is nearly to as-cast, and a lot of retained austenite decomposes when tempering at 350°C and the retained austenite decomposes almost until tempering at 560 °C. When tempering at 600 °C, the retained austenite in the alloys all decomposes. At 560°C the hardness is highest due to secondary hardening. The effect of nickel and manganese on the microstructure and properties of Fe-Cr-V-C cast alloy were also studied. The results show that the Fe-Cr-V-C cast alloy added nickel and manganese can obtain martensite matrix and much retained austenite microstructure, and nickel can also prevent pearlite transformation. With the increasing content of nickel and manganese, the hardness of as-cast alloy will decreases gradually, so one can improve the hardness of alloy by tempering process. When the content of nickel and manganese is 1.3-1.7%, the hardness of secondary hardening is the highest (HRC64). But when the content of nickel and manganese increase continually, the hardness of secondary hardening is low slightly, and the tempering temperature of secondary hardening rises.展开更多
文摘After different heat treatment processes, the metal compound, the microstructure and the hardness of the C-Cr-W- Mo-V-RE Fe-based hardfacing layers are investigated by means of metallographic microscope, X-ray diffraction （ XRD ）, energy dispersive spectrum（ EDS ）, transmission electron microscope（TEM） and hardness tester. The results show that the hardfacing layers have higher tempering stability and secondary hardening property. After quenching at 820 ℃ ,the hardness value（ HRC37 ） and the microstructure of the layers are similar to that normalized at 820 - 1 000 ℃. The tempering stability and the hardness increases with increasing quench temperature, which is attributed to the amount of the alloy element in the matrix. These results are very helpful for improving the mechanical properties of the hardfacing layers.
文摘The changes of tempering microstructure and properties of Fe-Cr-V-Ni-Mn-C cast alloys with martensite matrix and much retained austenite are studied. The results showed that when tempering at 200 °C the amount of retained austenite in the alloys is so much that is nearly to as-cast, and a lot of retained austenite decomposes when tempering at 350°C and the retained austenite decomposes almost until tempering at 560 °C. When tempering at 600 °C, the retained austenite in the alloys all decomposes. At 560°C the hardness is highest due to secondary hardening. The effect of nickel and manganese on the microstructure and properties of Fe-Cr-V-C cast alloy were also studied. The results show that the Fe-Cr-V-C cast alloy added nickel and manganese can obtain martensite matrix and much retained austenite microstructure, and nickel can also prevent pearlite transformation. With the increasing content of nickel and manganese, the hardness of as-cast alloy will decreases gradually, so one can improve the hardness of alloy by tempering process. When the content of nickel and manganese is 1.3-1.7%, the hardness of secondary hardening is the highest (HRC64). But when the content of nickel and manganese increase continually, the hardness of secondary hardening is low slightly, and the tempering temperature of secondary hardening rises.
