The Research Of The Reason Of Earring And Technically Solution Of H68 Copper Punching

The Copper alloy is a kind of polycrystalline material which is composed of weenie grains. All the component, the grain's size and it's tropism decide the mechanical property. When casting, rolling and heat treatment, the grain's component, size and tropism will be inflected. And then, the texture appeared. Here we study the reason of the earring, and search the way of reducing the earring from technics. I hope it's a good advice in production. From this article we can gain:In the first chapter we did some simply introduction of the Copper alloy's performance, the present situation of production and the significance of this topic. Then we analysis the reason of some kinds of textures, for example the texture of founding, heating distortion, cooling distortion and recrystallization, and then give some clew for the following's analysis.We know plastic strain ratio "r" reflects the property in punching of copperplate. The value of "r" is bigger; the ability in resisting attenuate is stronger. The value of anisotropic "Δr" reflects the planeness after punching. The value of "Δr" is closer to "0", the result of punching is better. From the deduction we can know that the "r", the "ε" (strain in width) and the "ε" (strain in length) have some connection in the area of plastic deformation. Then we can make a chart for our study. The copperplates of H68 were rolled to 3.0mm and 2.3mm,then they were annealed. After that we should roll them again for only once to various thickness. Then we found the tensile strength, the yield strength and extensibility hasn't some change, but the value of "r" and "Ar" have regularity when they were annealed again. Too big or too small screw-down rate of rolling is not good; the rate in 50%-75% is good.We tried to change the rate of temperature increasing and holding temperature in annealing, but it has big effect in the value of "r" and "Δr". When the rate is 25℃/min, the holding temperature is 490℃, time is 45min or when the rate is 25℃/min, the holding temperature is 490℃-520℃, time is 45min is good for our product.The change of increasing the depressing ratio of rolling before recrystallization annealing on 0.4mm/H68 can reduce the "Ar". Then we can assume that increasing the depressing ratio in finish rolling is good to copperplate's punching.