CP-Ti Corrosion Data: <0.13 mm/y Quick Reference
Updated : Aug. 11, 2025Why choose Commercially Pure Titanium?
- α‑phase CP‑Ti has low oxygen and high toughness; a **self‑passivating TiO₂ film** delivers outstanding oxidation resistance.
- In chloride media, seawater and mild acid/alkali environments it far outperforms 304L/316L stainless steel and can replace expensive Hastelloy while saving cost.
- High specific strength: density is only 60 % of steel, enabling ~40 % lighter pressure vessels and heat‑exchange equipment.
CP Ti Corrosion Rate Tables
How to read the following tables:
- E (Excellent) : corrosion rate < 0.127 mm/y
- G (Good) : 0.127 – 0.254 mm/y
- P (Poor) : > 0.254 mm/y
- "RT/B” denotes Room Temperature / Boiling conditions.
Corrosion in Organic Compounds
| Organic Compound | Concentration (%) | Temperature (RT/B) | Corrosion Rate mm/y (RT/B) | Rating |
|---|---|---|---|---|
| Tetrachloroethylene | 100 (vapor + liquid) | B | 0.0005 | E |
| Trichloromethyl Alkane | 100 | B | 0.0003 | E |
| Trichloromethane (H₂O) | - | B | 0.127 | E |
| Trichloroethylene | 99 | B | 0.00254 | E |
| Trichloroethylene "Stable” | 99 | B | 0.00254 | E |
| Formaldehyde | 37 | B | 0.127 | E |
| Formaldehyde + 2.5 % H2SO4 | 50 | B | 0.305 | G |
Except for the formaldehyde–sulphuric‑acid mixture, all media remain E‑rated even at boiling, demonstrating CP‑Ti’s superior stability in chlorinated organics.
Corrosion in Alkali Compounds
| Alkali | Concentration (%) | Temperature (RT/B) | Corrosion Rate mm/y (RT/B) | Rating |
|---|---|---|---|---|
| NaOH | 10 | - / B | - / 0.020 | - / E |
| NaOH | 20 | RT / B | < 0.127 / < 0.127 | E / E |
| NaOH | 50 | RT / B | < 0.0025 / < 0.0508 | E / E |
| NaOH | 73 | - / B | - / 0.127 | - / E |
| KOH | 10 | - / B | - / < 0.127 | - / E |
| KOH | 25 | - / B | - / 0.305 | - / G |
| KOH | 30 | 30 °C / B | 0.000 / 2.743 | E / P |
| NH4OH | 28 | RT / - | 0.0025 / - | E /- |
| Na2CO3 | 20 | RT / B | < 0.127 / < 0.127 | E / E |
| NH3 + 2 % NaOH | 20 | RT / - | 0.0708 /- | E /- |
Engineering note: 20‑50 % NaOH remains E‑rated even at boiling, ideal for caustic‑evaporator design; KOH ≥ 25 % requires temperature control or a Ti‑Mo alloy upgrade.
Corrosion in Organic Acids
| Organic Acid | Concentration (%) | Temperature (RT/B) | Corrosion Rate mm/y (RT/B) | Rating |
|---|---|---|---|---|
| Acetic Acid | 100 | RT / B | 0.000 / 0.000 | E / E |
| Oxalic Acid | 5 | RT / B | 0.127 / 29.390 | G / P |
| Oxalic Acid | 10 | RT / - | 0.008 / - | E / - |
| Lactic Acid | 10 | RT / B | 0.000 / 0.033 | E / E |
| Lactic Acid | 25 | RT / B | - / 0.028 | - / E |
| Formic Acid | 10 | - / B | - / 0.127 | - / G |
| Formic Acid | 25 | - / 100 °C | - / 2.440 | - / P |
| Formic Acid | 50 | - / 100 °C | - / 7.620 | - / P |
| Tannic Acid | 25 | RT / B | < 0.127 / < 0.127 | E / E |
| Citric Acid | 50 | RT / B | < 0.127 / < 0.127 | E / E |
| Stearic Acid | 100 | RT / B | < 0.127 / < 0.127 | E / E |
Key insight: Strong reducing acids (high‑strength oxalic/formic) can break down the Ti passive film—limit temperature or switch to Ta‑alloyed or β‑titanium grades.
Corrosion in Salt Solutions
All tested salt solutions show corrosion rates < 0.127 mm/y (E‑rating) at both room temperature and boiling.
(Media include FeCl₃, FeCl₂, CuCl₂, NH₄Cl, CaCl₂, MgCl₂, NiCl₂, BaCl₂, CuSO₄, (NH₄)₂SO₄, Na₂SO₄, PbSO₄, AgNO₃ and 16 other typical salts.)
This means CP‑Ti requires virtually no extra corrosion allowance in seawater, brine or most chloride/sulphate cooling & wash systems.
Corrosion in Inorganic Acids
| Inorganic Acid | Concentration (%) | Temperature (RT/B) | Corrosion Rate mm/y (RT/B) | Rating |
|---|---|---|---|---|
| Hydrochloric Acid | 1 | RT / B | 0.000 / 0.345 | E / G |
| Hydrochloric Acid | 5 | RT / B | 0.006 / 6.530 | E / P |
| Hydrochloric Acid | 10 | RT / B | 0.175 / 40.807 | G / P |
| Sulphuric Acid | 5 | RT / B | 0.000 / 13.01 | E / P |
| Sulphuric Acid | 40 | RT / - | 1.80 / - | P |
| Nitric Acid | 37 | RT / B | 0.000 / < 0.127 | E / E |
| Nitric Acid | 64 | RT / B | 0.000 / < 0.127 | E / E |
| Phosphoric Acid | 10 | RT / B | 0.000 / 6.400 | E / P |
| Phosphoric Acid | 30 | RT / B | 0.000 / 17.600 | E / P |
| Chromic Acid | 20 | RT / B | < 0.127 / < 0.127 | E / E |
| Aqua Regia (1 HNO₃ : 3 HCl) | - | RT / B | 0.000 / < 0.127 | E / E |
Bottom line: CP‑Ti remains E‑rated in nitric acid even at high strength & boiling; HCl ≥ 5 % or hot, concentrated H₂SO₄ require Ti‑Pd or Ti‑Mo alloys plus chloride control.
Material‑Selection & Design Tips
1. Heat Exchangers / Condensers
- Seawater cooling: no coating needed, tube life > 20 years.
- Chloride evaporators: keep KOH ≤ 20 % or upgrade to Grade 7.
2. Chemical‑process equipment
- CP‑Ti is first choice for chlorinated/fluorinated organics to avoid stress‑corrosion cracking.
- For aggressive oxalic/formic acids, lower temperature and design in‑situ cleaning.
3. Electrolysis & Electroplating
- Ti racks in CuSO₄, FeCl₃, AgNO₃ baths last 5‑10× longer.
- Electrolytes with < 10 % HCl need precious‑metal oxide coating on Ti surface.
From seawater cooling to organic‑solvent evaporation, CP‑Ti delivers near‑universal corrosion immunity. If you are evaluating materials for heat exchangers, pressure vessels or piping, email us for a medium‑specific selection solution and quote.
