Key points and quality control of titanium alloy forging process

1、 Process flow and technical parameters
The microstructure of titanium alloy ingots needs to be improved through open forging before forging processing. Due to the coarse grain size and poor plasticity of the as cast microstructure, there is a risk of cracking during the forging process, and the following process specifications should be followed:

1). temperature control

The initial forging temperature should be selected between 150-250 ℃ (950-1150 ℃ range) above the β phase transition point

After grain refinement, adjust to the upper part of α+β two-phase zone (950~1000 ℃)

Real time monitoring using contact thermometers throughout the entire process

2). Deformation control

Initial stage: Single deformation of 5% -8%

Mid term stage: gradually increase to 20% -30%

Final forging stage: dynamic adjustment based on tissue testing

2、 Key operating specifications
1). Hammer striking process
Adopting a three-stage hammering strategy of "light heavy stable"
Initial tap: frequency>40 times/min, single press amount<15mm
Heavy impact stage: Hydraulic hammer energy utilization rate ≥ 75%
Final forging stage: holding time ≤ 3s/time
2). Deformation management
Implement multi-directional forging process (upsetting → elongation → upsetting cycle)
Perform intermediate annealing when the cumulative deformation exceeds 70%
Control the total deformation of each fire by 50% -80%

3、 Quality risk prevention and control
1). Prevention of surface defects
Using graphite based high-temperature lubricant (coating thickness 0.2-0.5mm)
Preheating temperature of anvil ≥ 300 ℃
Edge part R angle>15mm
2). Organizational control
Configure infrared thermal imaging system with temperature difference control<30 ℃
β grain size ≤ 500 μ m (metallographic testing standard)
After each deformation, water cool to below 800 ℃
3). Crack prevention and control
Set strain rate sensitivity coefficient monitoring (m>0.3)
Ultrasonic online flaw detection frequency ≥ 2 times/fire time
Edge folding depth control<3mm
4、 Requirements for tooling equipment
Prioritize the use of CNC radial forging machines
Anvil surface aspect ratio 1:1.2-1.5
The stiffness coefficient of the forging press is ≥ 800kN/mm
Equipped with a rapid mold change system (with a change time of less than 30 minutes)

This process can increase the equiaxed rate of titanium alloy as cast microstructure to over 90% by precisely controlling thermodynamic parameters and deformation paths, effectively avoiding the occurrence of macroscopic defects and meeting the technical requirements of aviation grade forgings. In actual production, dynamic process optimization needs to be carried out based on the phase transition kinetics of materials.

Baoji Dingding Titanium Products Co., Ltd. specializes in producing high-quality medical titanium rods. Welcome to consult: 3412107@bjddt.com.