In order to investigate the distribution of Cu and Mg, and the effect of Cu on the microstructure of steels, manganese steels containing various Cu contents were annealed at 1260, 1100 and 1000℃, respectively, for I ...In order to investigate the distribution of Cu and Mg, and the effect of Cu on the microstructure of steels, manganese steels containing various Cu contents were annealed at 1260, 1100 and 1000℃, respectively, for I h and subsequently cooled to room temperature in the furnace to simulate the pre-rolling anneal. The results indicate that Cu is not microscopically segregated in the annealed steels. The scanning electron microscopy （SEM） observation shows that the main microstructure consist of ferrite and pearlite; the percentage of pearlite in the steels increases with increasing Cu content. The grain size reduces with the decrease of the annealing temperature. The results of energy dispersive X-ray analysis （EDXA） suggest that Cu content in pearlite is higher than that in ferrite, demonstrating that the microstructure-segregation of Cu occurred. However, the cast specimens show that Cu content in MnS and S-rich phases is high. In addition, Cu of 0.2%-0.4% could improve the distribution of MnS and S-rich inclusions. The optimal Cu content in steels and the optimal annealing temperature between 1100-1200℃ were determined.展开更多
Sintering shrinkage, compressive strength, bending strength, metallurgical morphology, microstructure and chemical composition diffusion of hydroxyapatite-316L stainless steel(HA-316L SS) composites were investigated....Sintering shrinkage, compressive strength, bending strength, metallurgical morphology, microstructure and chemical composition diffusion of hydroxyapatite-316L stainless steel(HA-316L SS) composites were investigated. The results show that the sintering shrinkage of HA-316L SS composites decreases from 27.38% to 8.87% for cylinder sample or from 27.18% to 8.62% for cuboid sample with decreasing the volume ratio of HA to 316L SS, which leads to higher sintering activity of HA compared with that of 316L SS. The compressive strength of HA-316L SS composites changes just like parabolic curve (245.3→126.3→202.8 MPa) with reducing the volume ratio of HA to 316L SS. Bending strength increases from 86.3MPa to 124. 2 MPa with increasing the content of 316L SS. Furthermore, comprehensive mechanical properties of 1.0∶3.0 (volume ratio of HA to 316L SS) composite are optimal with compressive strength and bending strength equal to 202.8 MPa and 124.2 MPa, respectively. The (microstructure) and metallurgical structure vary regularly with the volume ratio of HA to 316L SS. Some chemical reaction takes place at the interface of the composites during sintering.展开更多
In order to investigate the distribution of Cu and its effect on the microstructure of Cu-bearing steel, a series of mild steels containing different contents of Cu are developed by vacuum electric arc furnace. These ...In order to investigate the distribution of Cu and its effect on the microstructure of Cu-bearing steel, a series of mild steels containing different contents of Cu are developed by vacuum electric arc furnace. These steels are annealed at 1 260℃, 1 100 ℃ and 1 000℃ respectively for one hour and followed by furnace cooling to room temperature to simulate the heat treatment before the rolling process. The results show that Cu did not obviously segregate in annealed steels. The scanning electron microscope （SEM） observation show that the main microstruetures in Cu-bearing steel are ferrite and pearlite; The volume fraction of pearlite in steel increase with increasing Cu content. The grain size reduces with the decrease of annealing temperature. The results of energy dispersive X-ray analysis （EDXA） suggest that the Cu content in pearlite is higher than that in ferrite, which means that the microstructure-segregatian of Cu exists. However, the cast specimens show that Cu content in MnS and S-rich phase is very high, and Cu changed the distribution of/vinS in steel. In addition, the optimal Cu content in steel between 0.2%-0.4% and the optimal annealing temperature between 1 100-1 200℃are determined by the economical and practical principles.展开更多
基金the Major Program of National Natural Science Foundation of China （No. 50499336） National Basic Research Program of China （No. 2004CB619101）.
文摘In order to investigate the distribution of Cu and Mg, and the effect of Cu on the microstructure of steels, manganese steels containing various Cu contents were annealed at 1260, 1100 and 1000℃, respectively, for I h and subsequently cooled to room temperature in the furnace to simulate the pre-rolling anneal. The results indicate that Cu is not microscopically segregated in the annealed steels. The scanning electron microscopy （SEM） observation shows that the main microstructure consist of ferrite and pearlite; the percentage of pearlite in the steels increases with increasing Cu content. The grain size reduces with the decrease of the annealing temperature. The results of energy dispersive X-ray analysis （EDXA） suggest that Cu content in pearlite is higher than that in ferrite, demonstrating that the microstructure-segregation of Cu occurred. However, the cast specimens show that Cu content in MnS and S-rich phases is high. In addition, Cu of 0.2%-0.4% could improve the distribution of MnS and S-rich inclusions. The optimal Cu content in steels and the optimal annealing temperature between 1100-1200℃ were determined.
文摘Sintering shrinkage, compressive strength, bending strength, metallurgical morphology, microstructure and chemical composition diffusion of hydroxyapatite-316L stainless steel(HA-316L SS) composites were investigated. The results show that the sintering shrinkage of HA-316L SS composites decreases from 27.38% to 8.87% for cylinder sample or from 27.18% to 8.62% for cuboid sample with decreasing the volume ratio of HA to 316L SS, which leads to higher sintering activity of HA compared with that of 316L SS. The compressive strength of HA-316L SS composites changes just like parabolic curve (245.3→126.3→202.8 MPa) with reducing the volume ratio of HA to 316L SS. Bending strength increases from 86.3MPa to 124. 2 MPa with increasing the content of 316L SS. Furthermore, comprehensive mechanical properties of 1.0∶3.0 (volume ratio of HA to 316L SS) composite are optimal with compressive strength and bending strength equal to 202.8 MPa and 124.2 MPa, respectively. The (microstructure) and metallurgical structure vary regularly with the volume ratio of HA to 316L SS. Some chemical reaction takes place at the interface of the composites during sintering.
基金This project is supported by National Natural Science Foundation of China (No.50499336)National Basic Research Program of China (973 Program, No.2004CB619101).
文摘In order to investigate the distribution of Cu and its effect on the microstructure of Cu-bearing steel, a series of mild steels containing different contents of Cu are developed by vacuum electric arc furnace. These steels are annealed at 1 260℃, 1 100 ℃ and 1 000℃ respectively for one hour and followed by furnace cooling to room temperature to simulate the heat treatment before the rolling process. The results show that Cu did not obviously segregate in annealed steels. The scanning electron microscope （SEM） observation show that the main microstruetures in Cu-bearing steel are ferrite and pearlite; The volume fraction of pearlite in steel increase with increasing Cu content. The grain size reduces with the decrease of annealing temperature. The results of energy dispersive X-ray analysis （EDXA） suggest that the Cu content in pearlite is higher than that in ferrite, which means that the microstructure-segregatian of Cu exists. However, the cast specimens show that Cu content in MnS and S-rich phase is very high, and Cu changed the distribution of/vinS in steel. In addition, the optimal Cu content in steel between 0.2%-0.4% and the optimal annealing temperature between 1 100-1 200℃are determined by the economical and practical principles.
