The main purpose of annealing copper is to soften it - Kehua

Do you know what is the purpose of annealing copper? The main purpose of using this product is to soften it and prevent breakage and shrinkage during heating. The temperature during annealing generally reaches about 550 degrees Celsius. If you are interested, please follow Kehua Xiaobian. Get up and understand! The purpose of annealing: 1. Reduce hardness and improve machinability. 2. Eliminate residual stress, stabilize size, reduce deformation and crack tendency; 3. Refine grains, adjust structure, and eliminate organizational defects. 4. Uniform material organization and composition, improve material properties or prepare organization for subsequent heat treatment. The main purpose of pure copper annealing is to soften it. When it needs to be bent to prevent breakage and shrinkage, it needs to be annealed. The pure copper annealing temperature is 500-700℃; the recrystallization start temperature of cold-work hardened copper is 200-300℃; the pure copper hot working temperature is 900-1050℃. Hard pure copper can be annealed to achieve good plasticity of soft copper, and the annealing temperature is generally 550℃～600℃. Annealed copper The effect of pure copper annealing on the mechanical properties of pure copper? It can be seen from the figure below that after annealing at the same temperature, the tensile strength and microhardness of cold-rolled pure copper have roughly the same trend of changing with the reduction, basically showing a trend of first decreasing and then increasing with the increase of the reduction. Compared with the mechanical properties of cold-rolled pure copper without annealing treatment, the strength and hardness of cold-rolled pure copper after annealing treatment show different degrees of decrease. After annealing at 180°C, when the reduction is 94.6%, the tensile strength of pure copper decreases from 383.2MPa after cold rolling to 174.6MPa, and the microhardness decreases from 84.17HV0.01 to 71.5HV0.01, which is close to The strength of annealed pure copper (200 ~ 240MPa), which shows that the work hardening of pure copper is eliminated when annealed at 180 ° C, and the reason may be recrystallized, which greatly reduces the strength value. Generally, after cold deformation of metal or alloy material, its hardness and strength value will decrease with the increase of annealing temperature. However, the strength and hardness of oxygen-free copper after cold-rolling and annealing at 200 °C are significantly higher than those after annealing at 180 °C. When the reduction is 90.5%, the tensile strength of cold-rolled pure copper annealed at 200℃ reaches 407.4MPa, and the microhardness also reaches 92HV0.01, which is close to the strength and hardness of cold-rolled pure copper with the same reduction. This is due to the low-temperature annealing hardening effect when pure copper is annealed at 200 °C, which is due to the blocking of movable dislocations in the deformed material and the movable dislocations in the dislocation walls generated by polygonalization during annealing. Influence of cold rolling and annealing process on the mechanical properties of pure copper 1. The strength of pure copper after multi-pass special cold rolling is significantly improved. When the reduction is 90.3%, the highest strength is 439.3MPa, which is higher than that of conventional cold-worked pure copper. The strength is increased by 18.7%, and it has a better strain strengthening effect. 2. After cold-rolled pure copper is annealed at 180°C and 200°C, its tensile strength and microhardness are significantly lower than those of unannealed cold-rolled pure copper, and the change trend with the reduction is roughly the same, basically showing The trend of decreasing first and then increasing with the increase of reduction. 3. When the reduction is 94.6%, after cold-rolled pure copper is annealed at 180 °C, its tensile strength value is reduced from 383.2MPa after cold-rolling to 174.6MPa, and its microhardness is reduced from 84.7HV0.01 to 71.5HV0 .01, and the elongation was increased from 0.03% to 1.05%, and better comprehensive properties were obtained. 4. When cold-rolled pure copper is annealed at 200 °C, there will be a low-temperature annealing hardening effect. When the reduction is 90.5%, the annealed copper at 200 °C is the relevant introduction to annealed copper. If you are using pure copper, in When annealing, it is best to control the temperature at 200 degrees Celsius, which can effectively prevent the occurrence of lock-up. If you want to know more information, please pay more attention to the Kehua website!