Repeated solid solution aging thermal treatment process of titanium alloy

Abstract

The invention relates to a repeated solid solution aging thermal treatment process of titanium alloy. The process includes the steps that a titanium alloy forge is subjected to heat preservation at the temperature T for t minutes, wherein T is larger than or equal to Tbeta-15 DEG C but smaller than or equal to Tbeta+15 DEG C, t is equal to eta*delta max, delta max is the maximum section thickness of the forge and is shown in millimeters, and eta is the heating coefficient and ranges from 0.2 min / mm to 0.8 min / mm; then the forge is discharged out of a furnace to be air-cooled or wind-cooled or water-cooled to be at the room temperature, then the cooled forge is subjected to heat preservation at the temperature of T for t minutes, wherein T is larger than or equal to Tbeta-25 DEG C but smaller than or equal to Tbeta-50 DEG C, the computational formula of t is as above, namely t=eta*delta max, and the heating coefficient eta ranges from 0.3 min / mm to 1.2 min / mm; then the forge is discharged out of the furnace to be air-cooled or wind-cooled or water-cooled to be at the room temperature, the cooled forge is subjected to heat preservation at the temperature T ranging from 540 DEG C to 600 DEG C, and the heat preservation time t ranges from 0.5 hour to 2 hours; the forge is discharged out of the furnace to be air-cooled to be at the room temperature, the cooled forge is subjected to heat preservation at the temperature T ranging from 400 DEG C to 540 DEG C, and the heat preservation time t ranges from 4 hour to 24 hours; and then the forge is discharged out of the furnace to be air-cooled to be at the room temperature. The repeated solid solution aging thermal treatment process of the titanium alloy is suitable for thermal treatment of near-beta type, metastable beta type and steady beta type ultrahigh-toughness titanium alloy so as to obtain required microscopic structures with high overall performance and multi-scale precipitated phases mixed.

Description

technical field [0001] The invention relates to a precise control-based multiple solid solution aging heat treatment process for titanium alloys. Background technique [0002] In the past, under the guidance of strength design and stiffness design ideas, titanium alloys have experienced the development process from low-strength, medium-strength to high-strength and ultra-high-strength. In this development process, although the strengthening and toughening heat treatment process of titanium alloy has been the direction of people's efforts, it is difficult for conventional heat treatment to solve the optimal matching problem between high strength-high plasticity-high fracture toughness and so on. The general situation is that when high strength is obtained (for example, using ordinary solution aging strengthening heat treatment process, that is, single solution aging process), it is difficult to obtain forgings with high plasticity and high fracture toughness at the same time....

AI Technical Summary

Problems solved by technology

In this development process, although the strengthening and toughening heat treatment process of titanium alloy has been the direction of people's efforts, it is difficult to solve the optimal matching problem between high strength-high plasticity-high fracture toughness and so on by conventional heat treatment.

The general situation is that when high strength is obtained (for example, using ordinary solution aging strengthening heat treatment process, that is, single solution aging process), it is difficult to obtain forgings with high plasticity and high fracture toughness at the same time.

Under the conditions of traditional design ideas and conventional technology, the best match of high strength / ultra-high strength-high plasticity-high toughness of titanium alloy is difficult to break through in practical applications.

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