摘要
Effect of the austenitizing temperature on the microstructure,strength, and toughness of 16NiCo and 23NiCo alloys was studied. With increasing austenitizing temperature, the reductions in strength and hardness are probably caused by the coarsening of M_2C carbides. The use of higher austenitizing temperature resulted in improved impact toughness due to the dissolution of undissolved (Cr, Fe, Mo)_(23)C_6 carbides.As the austenitizing temperature is increased to 1050℃ for 16NiCo and 23NiCo alloys impact toughness levels are reduced on average by 31 and 53 J/cm￣2 respectively.The use of 1050℃ austenitizing temperatures resulted in intergranular fracture for 23NiCo alloy in 482℃ aged condition. It was suggested that this grain boundary embrittlement was the result of the formation of cementite particles during ageing.
Effect of the austenitizing temperature on the microstructure,strength, and toughness of 16NiCo and 23NiCo alloys was studied. With increasing austenitizing temperature, the reductions in strength and hardness are probably caused by the coarsening of M_2C carbides. The use of higher austenitizing temperature resulted in improved impact toughness due to the dissolution of undissolved (Cr, Fe, Mo)_(23)C_6 carbides.As the austenitizing temperature is increased to 1050℃ for 16NiCo and 23NiCo alloys impact toughness levels are reduced on average by 31 and 53 J/cm￣2 respectively.The use of 1050℃ austenitizing temperatures resulted in intergranular fracture for 23NiCo alloy in 482℃ aged condition. It was suggested that this grain boundary embrittlement was the result of the formation of cementite particles during ageing.
