Formulated control method for the shortest holding time of TC17 titanium alloy β forging

Abstract

The present invention belongs to the field of metallurgical manufacturing technology, and specifically relates to a formulaic control method for the shortest holding time of TC17 titanium alloy beta forging heating. The technical solution of the present invention is as follows: a formulaic control method for the shortest holding time of TC17 titanium alloy beta forging heating, wherein the shortest holding time of TC17 titanium alloy beta forging heating includes the shortest holding time of two-phase region heating and the shortest holding time of β-phase region heating, and the shortest holding time of two-phase region heating is calculated according to the following formula: shortest holding time of two-phase region heating = two-phase region uniformity coefficient × effective thickness of billet; the shortest holding time of β-phase region heating is calculated according to the following formula: shortest holding time of β-phase region heating = β-phase region uniformity coefficient × effective thickness of billet + 30min. The formulaic control method for the shortest holding time of TC17 titanium alloy beta forging heating provided by the present invention calculates the shortest holding time of β-forging heating through the maximum effective cross-sectional thickness of the TC17 billet, thereby solving the technical problem of difficult control of β grains.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgical manufacturing, and in particular relates to a formulaic control method for the shortest holding time of TC17 titanium alloy beta forging heating. Background Art

[0002] During the cross-β forging process of TC17 titanium alloy, large-sized forgings with complex cross-sections are usually encountered. The heat-through time of billet sections of different thicknesses is different, and the heat-through time of the billet surface and core is also different. If the heating time is too short, the core of the billet cannot be heated through. If the heating time is too long, the grain size of the metal on the outside of the billet may grow too large and affect the final performance. This requires a minimum holding time for heating of TC17 titanium alloy β forging, which can ensure that the core of the billet is heated through and that the β grains do not grow rapidly, avoiding the so-called "β brittleness" that may cause serious reduction in the plasticity of the material. Therefore, it is necessary to accurately calculate the shortest holding time for heating the TC17 titanium alloy cross-β forging billet to the β single-phase region above the phase transformation point. Summary of the Invention

[0003] The present invention provides a formulaic control method for the shortest holding time of TC17 titanium alloy beta forging heating. The shortest holding time of beta forging heating is calculated based on the maximum effective cross-sectional thickness of the TC17 billet, thereby solving the technical problem of difficult control of beta grains.

[0004] The technical solutions of the present invention are as follows:

[0005] Formulated control method for the shortest holding time of TC17 titanium alloy β forging heating. The shortest holding time of TC17 titanium alloy β forging heating includes the shortest holding time for two-phase zone heating and the shortest holding time for β phase zone heating. The shortest holding time for two-phase zone heating is calculated according to the following formula: Shortest holding time for two-phase zone heating = Two-phase zone uniformity coefficient × Effective thickness of billet; The shortest holding time for β phase zone heating is calculated according to the following formula: Shortest holding time for β phase zone heating = β phase zone uniformity coefficient × Effective thickness of billet + 30min.

[0006] Furthermore, in the formulaic control method for the shortest holding time of TC17 titanium alloy β forging heating, the effective thickness of the billet is the maximum effective cross-sectional thickness of the billet.

[0007] Furthermore, the formula control method for the shortest holding time of TC17 titanium alloy beta forging heating has a two-phase region uniformity coefficient of 0.7-0.8 min / mm.

[0008] Furthermore, the formulaic control method for the shortest holding time of TC17 titanium alloy β forging heating, the β phase region heat uniformity coefficient: when the effective thickness of the billet is 100-200mm, its value is 0.3-0.4; when the effective thickness of the billet is 200-300mm (excluding 200mm), its value is 0.32-0.42; when the effective thickness of the billet is 300-510mm (excluding 300mm), its value is 0.35-0.45.

[0009] Furthermore, in the formulaic control method for the shortest holding time of TC17 titanium alloy β forging heating, the selection of the heat uniformity coefficient of the β phase region is based on the complexity of the billet shape, and the value is selected from simple to complex and from small to large.

[0010] The beneficial effects of the present invention are as follows: the present invention calculates the shortest holding time of β forging heating through the maximum effective cross-sectional thickness of the TC17 billet, thereby solving the technical problem of difficult control of β grains. DETAILED DESCRIPTION

[0011] Formulated control method for the shortest holding time of TC17 titanium alloy β forging heating. The shortest holding time of TC17 titanium alloy β forging heating includes the shortest holding time for two-phase zone heating and the shortest holding time for β phase zone heating. The shortest holding time for two-phase zone heating is calculated according to the following formula: Shortest holding time for two-phase zone heating = Two-phase zone uniformity coefficient × Effective thickness of billet; The shortest holding time for β phase zone heating is calculated according to the following formula: Shortest holding time for β phase zone heating = β phase zone uniformity coefficient × Effective thickness of billet + 30min.

[0012] Among them: the effective thickness of the billet is the maximum effective cross-sectional thickness of the billet; the thermal uniformity coefficient of the two-phase region is 0.7-0.8min / mm; the thermal uniformity coefficient of the β phase region: when the effective thickness of the billet is 100-200mm, its value is 0.3-0.4; when the effective thickness of the billet is 200-300mm (excluding 200mm), its value is 0.32-0.42; when the effective thickness of the billet is 300-510mm (excluding 300mm), its value is 0.35-0.45; the selection of the thermal uniformity coefficient of the β phase region is based on the complexity of the billet shape, and the values ​​are selected from simple to complex and from small to large.

[0013] The two-phase heating temperature of TC17 titanium alloy is T β -(20-50)℃, the heating temperature of β phase is T β +(20-40)℃,T β is the phase transition point temperature of the alloy; after the furnace temperature reaches the specified two-phase zone heating temperature, the billet is loaded into the furnace, kept warm for the specified holding time, and then heated to the specified β-phase zone heating temperature and kept warm for the specified holding time.

[0014] Through cylindrical simulation heating coefficient, heat penetration of scaled-down parts, and verification of the heating process window, a realistic heating finite element simulation model was established by combining dynamic measurement of the billet's center temperature using deeply embedded thermocouples with coupled finite element simulation. Heat transfer boundary conditions for finite element simulation of the heating process of any billet were obtained, and a finite element model for heating billets of any shape was established. The minimum heat penetration time for the core of any billet was calculated. Through actual temperature measurements, verification of the heating model, and determination of grain size during long and short heating periods, the heating coefficients for billets of different sizes were determined, verifying the accuracy of the heating model and the grain size growth patterns.

[0015] Example

[0016] The effective thickness of a TC17 titanium alloy billet is 250mm. The minimum holding time for heating in the two-phase region is: 0.7 × 250 = 175 minutes, 0.8 × 250 = 200 minutes, with an optional range of 175-200 minutes. The minimum holding time for heating in the β-phase region is: 0.32 × 250 + 30 = 110 minutes for a simple billet shape; 0.37 × 250 + 30 = 122.5 minutes for a general billet shape; and 0.42 × 250 + 30 = 135 minutes for a complex billet shape.

Claims

1. A formulaic control method for the shortest holding time of TC17 titanium alloy β forging heating, characterized in that: The shortest holding time for β forging heating of TC17 titanium alloy includes the shortest holding time for heating in the two-phase zone and the shortest holding time for heating in the β phase zone. The shortest holding time for heating in the two-phase zone is calculated according to the following formula: the shortest holding time for heating in the two-phase zone = the uniformity coefficient of the two-phase zone × the effective thickness of the billet; the shortest holding time for heating in the β phase zone is calculated according to the following formula: the shortest holding time for heating in the β phase zone = the uniformity coefficient of the β phase zone × the effective thickness of the billet + 30min; the uniformity coefficient of the two-phase zone is 0.7-0.8 min / mm; the uniformity coefficient of the β phase zone: when the effective thickness of the billet is 100-200 mm, its value is 0.3-0.4; when the effective thickness of the billet is 200-300 mm, excluding 200 mm, its value is 0.32-0.42; when the effective thickness of the billet is 300-510 mm, excluding 300 mm, its value is 0.35-0.

45.

2. The method for formulating and controlling the shortest holding time of TC17 titanium alloy β forging heating according to claim 1, characterized in that: The effective thickness of the blank is the maximum effective cross-sectional thickness of the blank.

3. The method for formulating and controlling the shortest holding time of TC17 titanium alloy β forging heating according to claim 1, characterized in that: The selection of the heat dissipation coefficient of the β phase region is based on the complexity of the billet shape, and the value is selected from small to large from simple to complex.