Analysis of titanium forging manufacturing process technology!

I. Main forging methods of titanium forgings

1. Free forging

Applicable to forgings with simple shapes and low precision requirements, relying on manual operation, and low material utilization rate.

The process is flexible, but the deformation and hammering frequency need to be strictly controlled.

2. Die forging process

Open die forging: using a die with flash groove, controlling the metal flow in stages, and removing the flash during final forging, suitable for batch production of complex shape forgings. titanium forging / Titanium Threaded Forged Fitting / Gr3 Pure Titanium Plate

Closed die forging: flash-free design, high material utilization rate, better precision, but strict requirements on die strength and temperature control.

3. Extrusion and rolling

The extrusion process is extruded through the die hole, suitable for long strip/tube forgings, with high material density, but large equipment investment.

Rolling controls the shape through continuous deformation, with high efficiency, and can accurately adjust the size of the plate/profile.

2. Core process flow

1. Open forging

The initial temperature is selected to be 150-250℃ above the β phase transformation point, and the "light-heavy-stable" three-stage hammering strategy is adopted. Intermediate annealing is required when the cumulative deformation is greater than 70%.

Multi-directional forging cycle improves the uniformity of the organization, and the deformation of each fire is controlled at 50%-80%.

2. Special process optimization

U-shaped titanium alloy forgings adopt a "one"-shaped step billet design, which is formed by special tire molds and punches in steps. The cross-section of the bar is 1.1-1.25 times that of the rough shape to improve the accuracy.

Right-angle trapezoidal forgings optimize the deformation distribution through multi-fire forging, and the single deformation is 20%-50%.

3. Key points of quality control

1. Temperature and lubrication

The temperature fluctuation is monitored by infrared thermal imaging throughout the process, and the final forging temperature must be higher than the critical value of β brittleness to avoid cracks.

Graphite-based lubricants are used to reduce mold friction, and the R angle of the corners is greater than 15mm to prevent stress concentration.

2. Organization and defect prevention and control

β brittleness is repaired by controlling the heating temperature and plastic deformation.

The residual casting structure needs to ensure that the forging ratio is greater than 3:1, and the deformation rate in the final forging stage is dynamically adjusted.

IV. Heat treatment process

1. Quenching and tempering

α+β type titanium forgings need to be quenched after preheating at 600-650℃, and the tempering temperature is 400-500℃.

2. Solution and aging

α+β type solution treatment temperature is 980℃, and β type is treated at 775-900℃; aging temperature is 480-600℃, and it lasts for 2-16 hours to precipitate strengthening phase.