Corrosion Resistant Fasteners

Fasteners such as bolts, nuts and washers are critical components used in many demanding corrosive environments. Historically these fasteners have been plagued by failure due to corrosion. Failures can cause safety concerns and, in most cases, causes large operating and component replacement cost.

Typically fasteners are stainless steel or nickel alloys like Hastelloy® and are susceptible to corrosion. However, Tantalum is recognized as the most corrosion resistant metal commercially available. Furthermore, the cost of solid Tantalum components such fasteners is prohibitive and, in some cases, the mechanical properties of solid Tantalum is inferior to that of stainless steel.

Tantaline combines the benefits of corrosion protection of Tantalum at a much lower economical cost, all the while retaining the mechanical strength of the base material typically stainless steel. Tantaline® treatment provides superior corrosion resistance in a host of hot corrosion environments and has particularly shown to extend equipment service life and reduce maintenance costs in many Chemical, Pharmaceutical, Oil & Gas, Semiconductor, Geothermal and Mining industries.

Need Something Different?

Benefits

Tantaline® treatment uses high-end Chemical Vapor Deposition techniques to deposit a uniform, diffusion bonded layer of corrosion resistant tantalum onto very intricate shapes and smaller sizes of fittings while maintaining critical tolerances. Tantaline® treated fittings offer better corrosion resistance than austenitic stainless steels which cannot fight stress corrosion, chloride attack, and especially sulfide cracking. The metallurgical properties of the tantalum surface combined with the uniform and conformal CVD layer results in superior acid resistant fittings that have excellent compatibility in most aggressive acids and can be offered with economical pricing and short lead-times.

Use

MARKET	TYPICAL PROCESSES
Chemical Processing	Hot acids, wet and dry chlorine, sulfur compounds, sour gases containing hydrogen sulfide (H₂S) compounds
Oil & Gas	Acid gases (CO₂, H₂S, SO₂), ammonia (NH₃), hydrogen cyanide (HCN), alkylation, and amine derivatives
Pharmaceutical	Oxidizing agents including hydrogen peroxide (H₂O₂), bromine (Br), chlorine (Cl), nitration, and various cleaning chemistries
Semiconductor	Strong HCl etchants, corrosive Nital (alcohol + nitric acid), byproducts of Silicon deposition process
Mining	Strong acid leaching, pressure oxidation, heap leaching
Marine	Corrosive sea water with chlorides, dissolved oxygen (O₂), microbial corrosion

Key Technical Information

Hastelloy®* Inconel®**, Zirconium, Titanium, and Stainless Steel valve components are susceptible to Stress Corrosion Cracking (SCC) and pitting especially in hot acids like HCl. Tantaline® treatment offers the following beneficial characteristics:

Chemically resistant to SCC and pitting in many aggressive media and environments.
Tantalum layer remains passivated and inert to corrosion under high temperature (>200⁰ C) acidic conditions including concentrated hydrochloric acid (HCl) and sulfuric acid (H2SO4).***
Superior corrosion resistance against wet, dry chlorine atmospheres, and other chlorinated environments.

*Hastelloy® is a registered trademark of Haynes International.
**Inconel® is a trademark of Special Metals Wiggin Limited.
***FJ, H. (n.d.). Properties of Tantalum for Applications in the Chemical Process Industry