Explosion cladding, roll bonding and weld overlay are the three ways to put a corrosion-resistant layer on a steel plate. Explosion cladding bonds metals in the solid state and works for almost any combination and thickness; roll bonding is economical for large volumes of standard stainless or nickel-alloy plate; weld overlay suits complex shapes but dilutes the alloy and adds heat. The right choice depends on the material combination, thickness, size and quantity.
The three methods at a glance
| Explosion cladding | Roll bonding (hot roll bonded) | Weld overlay | |
|---|---|---|---|
| How the bond forms | High-velocity impact, solid-state metallurgical bond (wavy interface) | Hot rolling of a sandwich pack at a steel mill; diffusion bond | Clad alloy is deposited by welding (strip, wire) onto the base |
| Material combinations | Almost any — including titanium, zirconium, tantalum and aluminium on steel | Metallurgically compatible pairs, mainly stainless steel and nickel alloys on carbon steel | Weldable alloys only; no titanium or zirconium on steel |
| Base thickness | Thin to very thick (Shockwave: base 1–1,000 mm) | Limited by mill rolling capacity | Any thickness |
| Clad layer | Full wrought alloy at its specified chemistry (Shockwave: 1–50 mm) | Wrought alloy, usually thin | Several weld layers needed to control dilution |
| Dilution and heat effects | None — no melting, no heat-affected zone in the clad | None in the clad layer | Base metal mixes into the first layers; heat input causes distortion and residual stress |
| Size | Large single plates (Shockwave: up to 60 m², 50 t) | Mill plate sizes | Any size, but slow over large areas |
| Best for | Thick or large components, reactive metals, transition joints, tube sheets, small and medium quantities | Large volumes of standard stainless or nickel-clad plate | Nozzles, complex geometries, repairs |
When to choose explosion cladding
- The combination cannot be fused or rolled: titanium, zirconium or tantalum on steel, or aluminium to steel (transition joints).
- The base is thick, for example heavy tube sheets or pressure-vessel heads.
- You need the clad layer at its full, undiluted chemistry for corrosion resistance.
- You need a few large plates quickly rather than a mill campaign.
When roll bonding or weld overlay makes sense
Roll-bonded plate is efficient when large tonnages of a standard combination (for example 316L on carbon steel) are ordered in mill sizes. Weld overlay is the practical choice for nozzles, flanges and complex shapes, and for repairs. Many projects combine them: explosion-clad shells and tube sheets with overlay-welded nozzles.
Why vacuum explosion cladding
Most explosion cladding happens in the open air. Shockwave clads inside a vacuum chamber, which removes air from between the plates before detonation. The result is an oxide-free, 100% dense bond, less explosive per plate and a weather-independent schedule. Every plate is 100% ultrasonically tested and tested per ASME SA-263/264/265 or EN 13445-2. See our clad plates and the full list of material combinations.
Frequently asked questions
What is the difference between explosion cladding and roll bonding?
Explosion cladding bonds metals by a high-velocity impact without melting and works for almost any combination and thickness. Roll bonding joins compatible metals by hot rolling at a steel mill and is economical for large volumes of standard plate.
Is explosion clad better than weld overlay?
For flat plates, tube sheets and heads, explosion clad gives an undiluted clad layer with no heat-affected zone. Weld overlay is better for nozzles and complex shapes.
Can titanium be roll bonded or overlay welded to steel?
No. Titanium and steel form brittle intermetallics when melted or rolled together, so titanium-clad steel is made by explosion cladding.
What is weld overlay cladding?
Weld overlay deposits a corrosion-resistant alloy onto a base metal by welding. The first layers mix with the base metal (dilution), so several layers are usually needed.
How thick can explosion clad plates be?
Shockwave clads base materials from 1 to 1,000 mm with clad layers from 1 to 50 mm, in single plates up to 60 m² and 50 tonnes.
Written by Joeri Hofstede, CEO of Shockwave Metalworking Technologies — vacuum explosion welding specialists since 1985.