Titanium alloy spherical shell superplastic shaping method

Abstract

This invention provides titanium alloy ball shell plastic forming method. Titanium alloy embryo material is filled into down film, heat preservation is done when it is heated by electric furnace to get the floor temperature, then fluid pressure machine press to form and temperature boost at the same time, the temperature stop when the highest temperature is reached, once cycle over. When temperature is down to 50-80 degree centigrade below floor temperature, the temperature begin to lift, forming begins when temperature reach floor temperature, and stop forming when temperature reaches the highest temperature, the second cycle over. The forming accomplished after several cycles. The forming temperature range is 800-900 degree centigrade, and only forming in processing of temperature boosting. The amplitude of fluctuation is 100 degree centigrade, forming velocity is 0.6mm / min-1.0mm / min. This invention can be used to the diameter less than 800 mm and different wall thickness titanium alloy ball shell forming. Pressure proof ball need by deep diving submersible is this technique method. The inner surface of the ball shell doesn't need process, and processing margin of outer surface and roof is very little.

Description

Technical field [0001] The invention belongs to the forming technology of titanium alloy products, and mainly proposes a superplastic forming method of a titanium alloy spherical shell. Background technique [0002] The pressure-resistant shell of deep submersibles (more than 6000 meters) is usually made of titanium alloy, but because titanium alloy has the characteristics of high strength, low plasticity, and difficult to form, the conventional forming method is hot stamping, and hot stamping has the following Disadvantages: ①The effective temperature zone for plastic deformation of titanium alloy is relatively narrow, coupled with the chilling effect of the mold, resulting in a rapid drop in the temperature of the slab, a large increase in deformation resistance, and a sharp drop in plasticity. It requires multiple heating and stamping to complete, which brings production Inconvenience: ②The deformation of each part of the sphere is uneven, some areas are thinned, and some are ...

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Problems solved by technology

[0002] The pressure shell of deep submersibles with a large depth (above 6000 meters) is usually made of titanium alloy, but because titanium alloy has the characteristics of high strength, low plasticity, and difficulty in forming, the conventional forming method is hot stamping, and hot stamping has the following Disadvantages: ①The effective temperature zone for plastic deformation of titanium alloy is narrow, coupled with the chilling effect of the mold, resulting in a rapid drop in the temperature of the slab, a large increase in deformation resistance, and a sharp decrease in plasticity. Inconvenient, ②The deformation of each part of the sphere is uneven, some areas are thinned, some are locally thickened, the machining allowance is large, the thermal effect of local deformation is serious, and the temperature rises, resulting in coarsening of the internal and external tissues, etc.

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