Cold-processing technology of Al-Mg alloys at liquid nitrogen temperature region

Abstract

The invention relates to a cold-processing technology of Al-Mg alloys at a liquid nitrogen temperature region, and belongs to the technical field of nonferrous metal. The cold-processing technology comprises the following steps of firstly performing hot rolling on cast ingots containing Er aluminum magnesium alloys at 390-430 DEG C, wherein the rolling reduction achieves 90%, and air cooling the cast ingots to room temperature so as to obtain intermediate hot rolled plates; and then, rolling the intermediate hot rolled plates at low temperature. The step of cold rolling at low temperature is performed through immersing the intermediate hot rolled plates in liquid nitrogen for about half an hour, so that the intermediate hot rolled plates are cooled to the temperature of the liquid nitrogen, then, rapidly taking out the cooled rolled plates, and cold rolling the cooled rolled plates at room temperature in the rolling direction; when each rolling pass is completed, immediately putting the rolled plates in the liquid nitrogen for cooling, wherein the rolling reduction of each rolling pass is 10%-15%, and the total rolling reduction is 60%; and finally, respectively performing a stretching test on the cold rolled plates at room temperature, and performing an impact test on the cold rolled plates at the temperature of the liquid nitrogen, wherein the tensile strength, the yield strength and the elongation rate of the rolled plates at the temperature region of the liquid nitrogen are notably higher than those of the rolled plates at the room temperature, and the impact power of the rolled plates at the temperature of the liquid nitrogen is higher than that of the rolled plates under the room temperature state. According to the preparation technology, not only can the intensity of the alloys at low temperature be obviously improved, but also a certain low temperature extension rate of the alloys can be guaranteed, so that an aluminum alloy material with excellent comprehensive properties at the low temperature is obtained.

Description

Technical field: [0001] The invention belongs to the technical field of nonferrous metals, and in particular relates to a processing technology of cold rolling in a liquid nitrogen temperature zone to prepare aluminum alloy plates with excellent comprehensive mechanical properties at low temperatures. technical background: [0002] The hot rolling process can break the coarse grains in the as-cast state, reduce or eliminate casting defects, and transform the as-cast structure into a deformed structure, thereby improving the processing performance of the alloy; however, the structure and properties of hot-rolled products are not uniform enough, and the thickness of the product Dimensions are also difficult to control. [0003] The cryogenic treatment process can effectively improve the mechanical properties and service life of steel materials, non-ferrous metals and composite materials, stabilize dimensions, improve uniformity, not damage workpieces, and have low cost. At pr...

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Problems solved by technology

The material prepared by cold rolling has excellent tensile strength, yield strength and elongation, but its impact energy is significantly reduced

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