ժҪ In this research the tempering behavior of a Cr-W-V steel was investigated. This new alloy with the composition of Fe-4.5Cr-2W-0.25V-0.1C was austenitized at 1000��C for 30 min and tempered at 500��C to 700��C for different times up to 100h. An OM analysis of the microstructure of air cooled and water quenched specimens before tempering showed that although in both conditions fully martensitic matrix formed, finer structure had formed in the water quenched specimens. The XRD and TEM results showed that the most stable carbides formed during tempering of the steel were M23C6 and M7C3, respectively. Other carbides such as M3C and M2C, formed in the first stages of tempering, and stable MC were also observed. The results showed that when the tempering time, temperature and cooling rate were increased, weight percent of extracted precipitates was increased. In addition, the formation rate of the stable carbides such as M23C6 and dissolution rate of the metastable carbides such as M3C and M2C were increased. The hardness results was revealed that tempering at 600��C and 700��C result in gradual decrease in hardness, but didn't observed significant changes in hardness at 500��C even for long tempering times.
Abstract��In this research the tempering behavior of a Cr-W-V steel was investigated. This new alloy with the composition of Fe-4.5Cr-2W-0.25V-0.1C was austenitized at 1000��C for 30 min and tempered at 500��C to 700��C for different times up to 100h. An OM analysis of the microstructure of air cooled and water quenched specimens before tempering showed that although in both conditions fully martensitic matrix formed, finer structure had formed in the water quenched specimens. The XRD and TEM results showed that the most stable carbides formed during tempering of the steel were M23C6 and M7C3, respectively. Other carbides such as M3C and M2C, formed in the first stages of tempering, and stable MC were also observed. The results showed that when the tempering time, temperature and cooling rate were increased, weight percent of extracted precipitates was increased. In addition, the formation rate of the stable carbides such as M23C6 and dissolution rate of the metastable carbides such as M3C and M2C were increased. The hardness results was revealed that tempering at 600��C and 700��C result in gradual decrease in hardness, but didn't observed significant changes in hardness at 500��C even for long tempering times.
Mohsen Asadi Asadabad. Tempering Behavior of 4��5Cr-2W-0.25V Steel[J]. �й������ڿ���, 2010, 17(10): 57-62.
Mohsen Asadi Asadabad. Tempering Behavior of 4��5Cr-2W-0.25V Steel. Chinese Journal of Iron and Steel, 2010, 17(10): 57-62.