GRADE PROFILE
Titanium grade 2 — 3.7035 / R50400
Titanium grade 2 is unalloyed titanium, 99% minimum. Its density of 4.51 is roughly half that of stainless, and it is practically indifferent to chlorides — seawater does not attack it. It is the material of marine condensers.
- Titanium
- PREN: does not apply to this family
- Cost index 550
- Welded · Seamless · Heat exchanger
- Ø 6 to 168 mm
When to choose it
On seawater condensers, in desalination, in chlorinated chemistry and on marine heat exchangers. Titanium forms an extremely stable oxide layer that chlorides do not break down: where the best super duplex has a margin, titanium has practical immunity.
The weight saving also counts on large bundles, where half the density changes the loads on the structure.
When not to choose it
In reducing acids, hydrofluoric acid and concentrated sulphuric acid in particular, which attack it. That is titanium's blind spot, and it is abrupt: outside its domain, it has no margin.
Without a strict shielded welding procedure. Titanium picks up oxygen, nitrogen and hydrogen when hot, and a poorly shielded weld becomes irrecoverably brittle. Shielding must cover the face, the root and the cooling zone.
Where a stainless will do. At cost index 550, it is only relevant if chlorides or weight govern.
Composition
| Element | % |
|---|---|
| Ti | ≥ 99 |
| Fe | ≤ 0.3 |
| O | ≤ 0.25 |
| C | ≤ 0.08 |
| N | ≤ 0.03 |
| H | ≤ 0.015 |
Mechanical properties
We only publish mechanical properties tied to a specific standard and product form — welded tube, seamless tube and bar do not share the same values, and the gap routinely exceeds 30%. The figures that apply to your specification appear on the material certificate; ask us at enquiry stage.
Designations and standards
| Reference | Designation |
|---|---|
| EN (numeric) | 3.7035 |
| EN (symbolic) | Ti2 |
| ASTM / AISI | Grade 2 |
| UNS | R50400 |
| JIS | — |
| AFNOR | — |
Tube product standards :
- ASTM B338
- ASTM B861
- ASTM B862
Availability
Welded, seamless and heat exchanger tube, Ø 6 to 168 mm, to ASTM B338, B861 and B862. Partner stock or mill depending on the size and quantity. EN 10204 3.1 material certificates supplied with the goods.
Related grades
- Titanium grade 7 (R52400) — the same titanium with palladium, for reducing media.
- 254 SMO (1.4547) — the stainless for seawater, simpler to fabricate.
- CuNi 70/30 (CW354H) — the copper route, with an antifouling effect titanium does not have.
My grade isn't listed → · PREN calculator → · Compare grades →
Frequently asked questions
- Why does titanium have no PREN?
- Because PREN is an empirical formula built on the chromium, molybdenum and nitrogen of stainless steels. Titanium contains none of these as alloying elements: the formula is meaningless, and assigning a value would be inventing a number.
- Titanium or 254 SMO for a marine condenser?
- Titanium if the water is warm or heavily loaded, or if weight matters; it has no chloride limit. 254 SMO if the fabricator has no qualified titanium procedure, or if connection to steel piping must stay simple.
- Does titanium foul?
- It has no antifouling effect, unlike copper-nickels: marine organisms settle on it. On a seawater condenser that means regular cleaning or circuit treatment.