How a Titanium Processing Plant Is Organised
A titanium processing plant turns ingot and bar into mill products and finished parts through a fixed sequence: incoming material control, billet preparation, forging or extrusion, machining, heat treatment, surface treatment and final inspection. Titanium's chemical reactivity and low thermal conductivity drive most of the equipment and parameter choices, so process control is applied at every step rather than only at the end of the line.
Incoming Material and Billet Preparation
Feedstock is titanium ingot or bar, ordered to bar and billet specifications such as ASTM B348 for bar and billet and GB/T 2965 for wrought bar. Each heat is checked for chemical composition, hardness and macrostructure before release to production.
Pretreatment: surface cleaning and removal of oxide scale so that the billet surface is free of contamination.
Sawing and machining: billets are cut to length and the skin is machined off to remove surface cracks and alpha-case.
Marking and traceability: heat number, grade and billet weight follow the material through every operation.
Forging and Extrusion
Forging and extrusion raise density and strength and shape the material for later operations. Press capacity, die design and thermal cycle are selected for the grade: alpha-plus-beta grades are worked below the beta transus to keep a fine structure, while ingot breakdown for high-temperature grades starts above the transus.
| Operation | Key control | Typical result |
|---|---|---|
| Billet heating | Uniform temperature, controlled atmosphere | Limited oxygen pick-up and alpha-case |
| Forging | Strain per pass, reheat frequency | Refined structure, closed porosity |
| Extrusion | Ram speed, glass lubricant, reduction ratio | Profiles and tube shells to size |
| Straightening | Warm or hot straightening under control | Straightness within the drawing tolerance |
Machining, Heat Treatment and Surface Treatment
Machining covers turning, milling, drilling and tapping. Because heat concentrates at the cutting edge, plants use sharp tooling, moderate surface speeds, generous feed, rigid set-ups and chloride-free coolant, and they avoid interrupted cuts that cause chipping and work hardening.
Heat treatment: annealing for stress relief and ductility, solution treatment for homogenisation, aging for strength; vacuum or controlled-atmosphere furnaces for critical parts.
Surface treatment: pickling, bright annealing, polishing, anodising, electroplating and spraying, chosen by product requirement.
Cleaning: iron contamination is removed before any thermal operation to prevent surface alloying and staining.
Quality Inspection and Shop-Floor Safety
Inspection is layered across raw material, in-process and finished goods: dimensional checks, mechanical testing, corrosion testing and ultrasonic or radiographic examination of critical sections. Certificates of analysis and test reports are issued per lot to EN 10204 type 3.1 practice.
Safe operation of a titanium plant depends on containment. Fine titanium powder and chips are flammable, so dust extraction, explosion-proof electrical equipment and fire prevention measures are mandatory, and chlorinated solvents are banned because they cause stress-corrosion cracking. Welding needs inert shielding, clean joints and controlled heat input to avoid porosity and cracking.
Frequently Asked Questions
Q: Why is billet skin machined off before processing?
Ingot and billet surfaces carry oxide scale, alpha-case and shallow cracks that would propagate into the finished part.
Q: Which heat treatments are used in a titanium plant?
Annealing for stress relief and ductility, solution treatment for homogenisation, and aging to raise strength, chosen per grade and section size.
Q: Why is chloride-free coolant specified?
Chloride residues attack titanium and can trigger stress-corrosion cracking in service, so fluids and cleaning agents are chloride free.
Q: How is welding controlled?
Joints are cleaned and dry, shielded with inert gas on both sides, and welded with controlled heat input to avoid porosity and cracking.
Q: What safety measures are required?
Dust extraction, explosion-proof equipment and fire prevention for the machining and powder areas, plus ventilation for pickling lines.
Q: What is checked before despatch?
Dimensions, chemistry, mechanical properties, corrosion testing and ultrasonic inspection, with a test certificate issued for each lot.
