Effect of annealing and cooling rate on toughness of G115 heat-resistant steels
Zhen Liu1, Li Gong1, Chi Zhang1, Zheng-dong Liu2, Zheng-zong Chen2, Yun-he Yu1
1 Key Laboratory for Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China; 2 Institute for Special Steels, China Iron and Steel Research Institute, Beijing 100081, China
Effect of annealing and cooling rate on toughness of G115 heat-resistant steels
Zhen Liu1, Li Gong1, Chi Zhang1, Zheng-dong Liu2, Zheng-zong Chen2, Yun-he Yu1
1 Key Laboratory for Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China; 2 Institute for Special Steels, China Iron and Steel Research Institute, Beijing 100081, China
摘要 The effects of annealing before normalizing and different cooling ways, i.e., air cooling, quenching, and water mist cooling after normalizing on the toughness of G115 steels were investigated. The impact tests showed that the annealed samples had better toughness compared to the unannealed samples for three cooling ways. Microstructure observations revealed that the annealed samples had a more uniform grain distribution, smaller size and area fraction of M23C6 particles along the grain boundaries, and lower dislocation density than those in the unannealed samples, which performed together for good toughness. Among three cooling ways, air cooling gave the best toughness due to the smallest occupancy of M23C6 particles in the grain boundaries. Thus, the combination of annealing conducted before normalizing and air cooling selected after normalizing can improve the toughness a lot of G115 steels.
Abstract：The effects of annealing before normalizing and different cooling ways, i.e., air cooling, quenching, and water mist cooling after normalizing on the toughness of G115 steels were investigated. The impact tests showed that the annealed samples had better toughness compared to the unannealed samples for three cooling ways. Microstructure observations revealed that the annealed samples had a more uniform grain distribution, smaller size and area fraction of M23C6 particles along the grain boundaries, and lower dislocation density than those in the unannealed samples, which performed together for good toughness. Among three cooling ways, air cooling gave the best toughness due to the smallest occupancy of M23C6 particles in the grain boundaries. Thus, the combination of annealing conducted before normalizing and air cooling selected after normalizing can improve the toughness a lot of G115 steels.
Zhen Liu,Li Gong,Chi Zhang, et al. Effect of annealing and cooling rate on toughness of G115 heat-resistant steels[J]. Journal of Iron and Steel Research International, 2022, 29(08): 1245-1256.
2022, Vol. 29 
