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Titanium and its alloys exhibit a unique combination of mechanical and physical properties and corrosion resistance which have made them desirable for critical, industrial, demanding aerospace, chemical and energy industry service.
Primary Attributes of Titanium Alloys
- Elevated Strength-to-Density Ratio (high structural efficiency)
- Low Density (roughly half the weight of steel, nickel and copper alloys)
- Exceptional Corrosion Resistance (superior resistance to chlorides, seawater and sour and oxidizing acidic media)
- Excellent Elevated Temperature Properties
List of Chemical environments where Titanium alloys are highly resistant & have been successfully applied
Generic media
| Typical examples | Guideline for successful use
| | Oxidizing Acids | HNO3, H2CrO4, HClO4
| | Reducing Acids
| HCl, HBr, HI, H2SO4, H3PO4, sulfamic, oxalic, trichloroacetic acids
| Observe acid conc./temp. limits, avoid HF solution
| Alcohols
| Methanol, ethanol, propanol, glycols
| Avoid dry (anhydrous) methanol, can cause SCC.
| Strong Alkaline solutions
| NaOH, KOH, LiOH
| Excessive hydrogen pickup and/or corrosion rates at higher temp. (75-80°C)
| | Mild Alkaline solutions | Mg(OH)2, Ca(OH)2, NH4OH, amines
| | Bleachants
| ClO2, chlorate, hypochlorites,wet Cl2, perchlorates, wet Br2, bromates
| | Chloride brines
| NaCl, KCl, LiCl
| | Gases
| O2, Cl2, Br2, I2, NO2, N2O4
| Ignition/burning possible in pure or enriched O2 gas, or dry halogen gases or red-fuming NO2(N2O4)
| | Other Gases | H2, N2, CO2, CO, SO2, H2S, NH3, NO
| Excessive hydrogen absorption in dry H2 gas at higher temp. & pressures
| Halogens
| Cl2, Br2, I2, F2 | Avoid dry halogens, need to be moist (wet) for good resistance. Avoid F2 & HF gases | Hydrocarbons
| Alkanes, alkenes, aromatics, etc. sweet and sour crude oil & gas | | Halogenated hydrocarbons
| Chloro-, chloro-fluoro-, or brominated alkanes, alkenes, or aromatics
| Need at least traces of water (10-100 ppm) for passivity
| Liquid metals
| Na, K, Mg, Al, Pb, Sn, Hg
| Observe temp. limitations. Avoid molten Zn, Li, Ga, or Cd
| Hydrolyzable metal halide solutions
| MgCl2, CaCl2, AlCl3, ZnCl2 | Observe temp./conc. guidelines
| Oxidizing metallic halide solutions
| FeCl3, CuCl2, CuSO4, NiCl2, Fe2(SO4)3
| | Organic acids
| TPA, acetic, stearic, adipic, formic, tartaric, tannic acids
| Observe temp./conc. guidelines for formic acid, & select Pd- or Ru-enhanced alloys if necessary
| Other organic compounds
| Aldehydes, ketones, ethers, esters, glycols
| | Salt solutions
| Sulfates, phosphates, nitrates, sulfites, carbonates, cyanates, etc.
| | Seawater
| Aerated, deaerated, contaminated, or slightly acidified condition
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