Grade 2 commercially pure titanium is the default material for chemical-plant corrosion service, and most titanium heat-exchanger tubing and vessel plate is Grade 2. It resists the chlorides and oxidizing acids that eat stainless steel, welds and forms well, and carries enough strength for pressure components. This guide covers what Grade 2 resists, where its limits are, which form to order for which component, and how to specify it.
Beiyu Titanium supplies Grade 2 titanium as tube, pipe, plate, sheet and bar for chemical and heat-exchanger service, to ASTM B338, B861, B862, B265 and B348. For chemical heat-exchanger material, add the required EN 10204 3.1 results and heat or lot identifiers to the RFQ so Beiyu can confirm the available document scope.
Why is Grade 2 the workhorse of chemical processing?
Grade 2 (UNS R50400) hits the balance a chemical plant needs. It carries the full corrosion resistance of commercially pure titanium, adds enough strength for piping and pressure parts, and stays weldable and formable for fabrication. Corrosion resistance is essentially the same across CP Grades 1 to 4, so Grade 2 is chosen over the softer Grade 1 whenever a component needs more strength, which covers most heat-exchanger and vessel work. For the full grade comparison, see our guide to choosing a CP titanium grade.
What corrosives does Grade 2 titanium resist?
Grade 2 owes its performance to a stable, self-healing oxide film. It holds up in the media that dominate chemical and marine service:
| Medium | Grade 2 behavior |
|---|---|
| Seawater and chloride solutions | Excellent, including moist and metallic chlorides |
| Oxidizing acids, such as nitric and chromic acid | Excellent resistance |
| Chlorine, chlorite and hypochlorite solutions | Resistant, a common bleach-plant material |
| Organic acids | Broadly resistant |
| Strong reducing acids, such as hot HCl or H2SO4 | Limited; step up to Grade 7 |
Because the passive film reforms in the presence of moisture and oxygen, Grade 2 shrugs off pitting and crevice corrosion in chloride service that would attack stainless steel.
What are Grade 2’s temperature and service limits?
Grade 2 keeps useful strength to about 400°F (200°C) and resists oxidation in air to roughly 600°F (315°C). Two limits decide when it is not enough:
- Strong reducing acids, such as hot hydrochloric or sulfuric acid: Grade 2 corrodes; the palladium-bearing Grade 7 is the step-up for reducing-acid service.
- Hot concentrated brines and crevices in hot service: Grade 12 improves crevice-corrosion resistance in hot chloride service.
Beiyu supplies both Grade 7 and Grade 12 titanium alongside Grade 2, so a plant can source the reducing-acid or hot-brine upgrade against the same supplier and documentation chain.
If the corrosion envelope is driven by reducing acids such as HCl or sulfuric acid rather than neutral or oxidizing chemistry, review how Grade 7 is used for reducing-acid titanium service before holding Grade 2 on the order line.
For hot brine and tight-crevice chloride service, compare the duty with where Grade 12 is used for hot brine and crevice-corrosion service before the specification stays with Grade 2.
Which form do you order for which component?
Chemical and heat-exchanger builds pull different Grade 2 mill products. Match the form and standard to the component:
| Component | Grade 2 form | Norm |
|---|---|---|
| Heat-exchanger and condenser tubing | Seamless or welded tube | ASTM B338 |
| Process piping | Seamless or welded pipe | ASTM B861 / B862 |
| Vessels, tube sheets, reactor plate | Platte und Blech | ASTM B265 |
| Shafts, fittings, machined parts | Stangen und Knüppel | ASTM B348 |
Beiyu supplies Grade 2 across all of these forms, so a heat-exchanger or process build can source Titanrohr Grade 2, a drawing-based Grade 2 titanium tube sheet, Bleche und Platten aus Titan Grade 2, and piping against one grade and one documentation chain. For tube specification detail, see our ASTM B338 titanium tube guide.
Where the exchanger uses a tank coil rather than a straight tube bundle, the Titan-Wärmetauscherwendel page shows the drawing and coil-geometry details to carry with the same Grade 2 tube basis.
A complete process package may also combine these mill forms with other Chemieanlagen and wetted components such as titanium ball valves; keep the medium, temperature and pressure basis consistent across the package.
When should you move off Grade 2?
Grade 2 covers most oxidizing and neutral chemical service, but three cases call for a different titanium grade:
| Service limit | Move to | Reason |
|---|---|---|
| Reducing acids such as hot HCl, H2SO4 or phosphoric acid | Grade 7 (Ti-0.15Pd) | Palladium improves reducing-acid resistance |
| Hot brine and crevice-prone chloride service | Grade 12 (Ti-0.3Mo-0.8Ni) | Mo/Ni improve hot chloride and crevice behavior |
| High mechanical load beyond CP strength | Ti-6Al-4V or another alloy | Strength requirement, not corrosion resistance |
When the service envelope is outside the suitable titanium grade, compare the specified medium and temperature with a nickel-alloy route such as Alloy 625 plate to ASTM B443 rather than forcing Grade 2 into the duty.
How do you specify and certify Grade 2 for chemical service?
A chemical or heat-exchanger RFQ should state grade, form, standard and dimensions, plus the service so the mill can confirm fit:
- Grade und Norm: Grade 2 to ASTM B338 (tube), B861/B862 (pipe), B265 (plate) or B348 (bar).
- Dimensions: OD and wall for tube; thickness for plate; diameter for bar.
- Condition and finish as the component requires.
- Certification: EN 10204 3.1 mill test certificate with chemistry and mechanical results tied to the heat number.
Beiyu reviews each line against mill capability and supplies Grade 2 for chemical, marine and oil and gas corrosion service, documented by heat number. See our chemical industry und marine engineering applications for where Grade 2 typically lands.
For seawater and marine service that stays inside Grade 2’s corrosion window, the sister guide on titanium in seawater and marine service shows where the same Grade 2 basis carries over into desalination and offshore systems.
How to read the Grade 2 certificate for chemical service
Grade 2’s corrosion behavior is inherent to the metal, so for chemical and heat-exchanger duty the certificate risk is not the alloy, it is the form and its testing:
- Chemistry basis. Confirm oxygen sits within the Grade 2 band, since oxygen sets strength, and iron is within limit; these are the two lines that define commercially pure Grade 2.
- Mechanicals by form. Plate, tube and bar are tested on different bases, so read yield and tensile against the standard for the form you ordered, B265 for plate, B338 for tube, B348 for bar.
- Tube testing for exchangers. On welded heat-exchanger tube, weld integrity is the real acceptance risk, not chemistry. ASTM B338 itself requires these tests, so confirm the eddy-current test on the weld, the hydrostatic or pneumatic test, and the flattening and flare results are all reported on the certificate rather than assumed.
Match the heat number to the tube or plate marking to close traceability. The trap for exchanger buyers is accepting a certificate that shows good chemistry but omits the tube test regime, because for welded tube the failure mode in service is the weld, not the base metal.
Welding Grade 2 equipment: the shield decides the service life
Most chemical-service Grade 2 goes into welded equipment, so weld quality is corrosion quality. The alloy itself welds readily; the risk is atmosphere, because titanium above roughly 480 degrees Celsius takes up oxygen and nitrogen and embrittles, so every heated zone, weld pool, root side and cooling metal needs inert-gas cover until it is cool. Weld colour is the working acceptance signal: silver is right, light straw is normally still acceptable, and blue, grey or powdery white means the shielding failed and the metal under that colour is suspect. For procurement, two lines carry the load: state that fabrication welds follow titanium shielding practice with colour acceptance, and repeat the weld-filler grade on the purchase order so seams match the drawing. When a palladium-bearing seam is specified for chemical service, Beiyu can quote ERTi-7 Titan-Schweißdraht as a separate filler line.
Hydriding: the quiet failure mode of titanium in service
Grade 2’s corrosion failure modes are covered above; the less-known one is hydrogen. In service, titanium can absorb hydrogen and form brittle hydrides when it is galvanically coupled to a more active metal, or held at strongly negative potentials by over-applied cathodic protection, with higher temperatures making it worse. The damage grows invisibly and shows up as cracking long after commissioning. The protections are design-side and cheap at design time: avoid uncontrolled couples with active metals, keep impressed-current protection within sensible potential limits for titanium, and raise the question explicitly when titanium tubes meet a protected steel shell. A buyer who flags the galvanic environment on the RFQ gives the material review a chance to catch this early.
Iron contamination: the cheapest failure to prevent
Titanium in a chemical plant usually fails at a detail, and embedded iron is the classic one. Steel tools, racks and grinding sparks leave iron particles in the titanium surface; in service these sites stain, break down the local passive film and can seed pitting that the clean alloy would resist. The rules cost almost nothing: dedicated or cleaned tools, separation from carbon steel in storage and fabrication, and a surface-iron check where the specification calls for one. On certified equipment work, embedded iron is a findable, failable defect; preventing it is a storage-layout decision.
Einkaufshinweise vom Export-Team
Chemical-equipment orders buy several forms at once, and the clean way to order is one specification line per form: plate to B265, tube to B338, bar to B348, seamless pipe to B861 and welded pipe to B862, each with its own dimensions and test scope, rather than one blanket titanium line. State the medium, concentration and temperature so the mill review checks the duty, not just the dimensions; name ASME SB dual certification up front where the fabricator does code work; and put the weld-filler grade on the order when the fabricator buys filler through the same channel. Beiyu reviews each chemical-service line against mill capability before quoting, with EN 10204 3.1 documentation and heat-number traceability by order scope.
Häufig gestellte Fragen
Is Grade 2 titanium good for seawater?
Yes. Grade 2 resists seawater and chloride corrosion, including pitting and crevice attack, which makes it a standard material for marine and desalination heat exchangers and piping.
What titanium grade is used for heat exchangers?
Grade 2 is the most common, supplied as ASTM B338 tube and B265 tube-sheet plate. Reducing-acid or hot-brine service may call for Grade 7 or Grade 12 instead.
What is the temperature limit for Grade 2 titanium?
Grade 2 holds useful strength to about 400°F (200°C) and resists oxidation in air to roughly 600°F (315°C); confirm against the specific service and code.
When is Grade 7 or Grade 12 needed instead of Grade 2?
Grade 7 for reducing acids such as hot hydrochloric or sulfuric acid; Grade 12 for hot concentrated brines and crevice-prone chloride service. Grade 2 covers most oxidizing and neutral media. Beiyu supplies all three.
References
- ASTM B265, B338, B348, B861 and B862, standard specifications for titanium mill products: astm.org
- AWS G2.4, Guide for the Fusion Welding of Titanium and Titanium Alloys (American Welding Society)
- EN 10204, Metallische Erzeugnisse, Arten von Prüfbescheinigungen (CEN)
Angebot für Titan Grade 2 anfordern
The RFQ-Checkliste is a useful final check for the grade, standard, dimensions, tolerance, quantity and documentation fields before submission.
If the RFQ is for Canadian code work, pair the grade-and-size checklist with our guide to titanium for Canadian pressure equipment so the material line names the ASME SB designation and the certificate chain the fabricator will carry into CRN review.
To quote Grade 2 titanium for chemical or heat-exchanger service, Beiyu needs: form (tube, pipe, plate, sheet or bar), standard, dimensions (OD and wall, or thickness), quantity, and the service or medium. Send the drawing or spec and we review each line against mill capability before quoting, with EN 10204 3.1 MTC and heat-number traceability by order scope. Kontaktieren Sie Beiyu Titanium für eine Anfrage.