The short answer: Titanium's corrosion resistance comes from a tightly adherent titanium-dioxide film that forms on its own, so passivating titanium does not improve the oxide the way it does on stainless. What passivation does is remove the iron and other surface contaminants that fabrication, tooling and handling leave behind — contaminants that corrode, stain and can embrittle the surface if left in place. Harrison passivates titanium assemblies of all sizes to ASTM B600 or your specification, mechanically polishes titanium to finishes certified as low as 4 µin Ra, and chemically and oxygen cleans titanium components for gas and high-purity service. Titanium is not electropolished.

Passivation of titanium

ASTM B600 (Standard Guide for Descaling and Cleaning Titanium and Titanium Alloy Surfaces) is the governing document. Harrison's process removes embedded iron from steel tooling and handling, scale and shop contamination, then verifies the surface is free of iron. Components that will see chloride, seawater, chemical-process or medical service, or that will be welded or coated, are passivated so the native oxide forms on a clean surface. Equipment that cannot ship is passivated on-site.

Mechanical polishing of titanium

Titanium is mechanically polished to improve surface finish, reduce product adhesion and improve cleanability on process equipment, marine hardware and medical and aerospace components. Harrison certifies finishes as low as 4 µin Ra with profilometer readings. Polishing titanium needs tooling and abrasives kept separate from steel to avoid re-contaminating the surface; Harrison's polishing team works that way as standard.

Chemical and oxygen cleaning

Titanium valves, fittings, heat-exchanger components and vessels for oxygen, industrial-gas, cryogenic and high-purity service are cleaned to CGA G-4.1 and ASTM G93 practice, verified and packaged clean; see oxygen cleaning. Chemical cleaning removes scale and process residues from titanium equipment in service.

Typical titanium components

Chemical-process heat exchangers, tubes and tubesheets, reactor and column internals, seawater and desalination hardware, marine and offshore components, aerospace structural and engine parts, medical and implant components, and gas-system hardware. Large assemblies are handled in Houston with four overhead cranes and 15,000 lb material-handling capacity.

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