A titanium clad plate is a steel plate with a layer of titanium metallurgically bonded to one side. The steel base carries the pressure and the structural loads; the titanium layer, usually only a few millimetres thick, resists the process medium. Titanium-clad steel gives the corrosion resistance of solid titanium in chloride, seawater and oxidising-acid service at a fraction of the material cost, and it can be designed and fabricated to ASME Section VIII and EN 13445 like a normal steel vessel.
Why titanium clad plate is made by explosion welding
Titanium cannot be fusion welded to steel. When the two metals melt together they form brittle titanium–iron intermetallic compounds (TiFe, TiFe2) that crack under load. Roll bonding and weld overlay are therefore not practical for titanium on steel.
Explosion welding solves this by bonding the metals in the solid state: a controlled detonation accelerates the titanium onto the steel, the impact cleans both surfaces and joins them in a fraction of a millisecond, and no melting zone with intermetallics is formed. That is why explosion cladding is the standard production route for titanium clad plate worldwide. Shockwave carries out the bonding inside vacuum chambers, which minimises oxidation at the interface and gives a consistent bond from plate to plate.
Titanium grades and base materials
| Item | Typical choice |
|---|---|
| Titanium clad layer | Grade 1 (best formability), Grade 2 (most common), Grade 7 and Grade 11 (palladium-alloyed, for reducing acids and crevice corrosion), Grade 12 (Ni-Mo alloyed) |
| Titanium plate specification | ASME SB-265 / ASTM B265 |
| Base material | SA516 Gr. 60/70, P265GH / P355 pressure-vessel steel, SA266 or SA350 forgings for tube sheets |
| Clad plate specification | ASME SB-898 (reactive and refractory metal clad plate) plus the customer specification |
| Formats | Flat plates, discs, tube sheets and head blanks; plates up to 60 m² and 50 metric tonnes |
The full list of clad layers and bases we process is on the clad plate material combinations page.
Standards and testing
ASME SB-898 requires a bond shear test on every clad plate, with a minimum shear strength of 137.9 MPa (20 ksi), plus ultrasonic inspection of the bond to an agreed acceptance level. At Shockwave every production plate also gets:
- 100% automated phased-array ultrasonic scan of the full bond area
- Bond shear and through-thickness tensile tests on a stamped, traced test coupon, also after simulated PWHT cycles when specified
- Bend tests, PMI (XRF) and hardness checks
- Third-party and class inspection on request (LR, DNV, ABS and others)
Heat treatment and fabrication
Because titanium and steel react at high temperature, post-weld heat treatment of titanium-clad equipment is limited in temperature and time. The PWHT cycle should be agreed with the clad plate manufacturer before ordering, so the bond can be qualified on test coupons that have seen the same cycle.
Titanium-clad shells are not welded through. The usual joint design is:
- Strip back the titanium layer along the seam and weld the steel base with a normal carbon-steel procedure.
- Fit a titanium filler strip in the gap, then weld a titanium batten (cover) strip over the joint to the titanium cladding only.
- Weld the titanium with full inert-gas shielding (trailing and back shielding) to avoid embrittlement, and leak test the batten strips through tell-tale holes.
More on joint details in how to weld clad plates.
Where titanium clad plate is used
- PTA and chemical plants — reactors, crystallisers and columns in purified terephthalic acid, chlor-alkali and other chloride or oxidising-acid processes
- Heat exchangers — tube sheets for seawater-cooled exchangers and power-plant condensers with titanium tubes
- Desalination — evaporator and heat-exchanger components in seawater service
- Metals processing — autoclaves and vessels in hydrometallurgical processes
- Transition joints — titanium is also used in transition joints such as Inox-Triplate® and CryoClad®
Titanium clad vs solid titanium
Solid titanium is the simplest choice for thin-walled equipment. Once wall thickness rises — high pressure, large diameter or thick tube sheets — titanium clad plate becomes much cheaper, because only the wetted layer is titanium and the strength comes from steel. Clad equipment can also be designed with the higher allowable stresses of steel, and attachments and supports can be welded to the steel side with standard procedures.
Ready to quote? Send the base and clad grades, thicknesses, plate size and quantity through our contact page, or read more about clad plates and pressure vessel cladding.
Frequently asked questions
What is titanium clad plate?
A steel plate with a layer of titanium metallurgically bonded to one side, usually by explosion welding. The steel carries the load and the titanium resists corrosion.
Can titanium be welded to steel?
Not by fusion welding: titanium and iron form brittle intermetallic compounds. Titanium is bonded to steel in the solid state by explosion welding, which is how titanium clad plate is made.
Which standard covers titanium clad plate?
ASME SB-898 (ASTM B898) covers reactive and refractory metal clad plate, including titanium on steel. It requires a bond shear strength of at least 137.9 MPa (20 ksi) and ultrasonic inspection of the bond.
Which titanium grades are used for cladding?
Mostly Grade 1 and Grade 2 commercially pure titanium. Grade 7, 11 and 12 are used where better resistance to reducing acids or crevice corrosion is needed.
Can titanium clad plate be heat treated?
Yes, but the post-weld heat treatment temperature and time are limited to protect the bond. Agree the PWHT cycle with the manufacturer so the bond can be tested after a simulated cycle.
What is titanium clad plate used for?
Reactors and columns in PTA and chlor-alkali plants, tube sheets for seawater heat exchangers and condensers, desalination equipment and autoclaves in metals processing.
Written by Joeri Hofstede, CEO of Shockwave Metalworking Technologies — vacuum explosion welding specialists since 1985.