Surface Engineering To Improve Metal Hardness Fatigue Resistance And Reduce Corrosion At Offshore Europe Stand 4D83 Wallwork Group

Offshore Europe is the showcase for heat treatment and surface engineering specialist, the Wallwork Group, offering metal treatments that improve wear resistance, fatigue strength and corrosion resistance of systems and components in offshore plant. Based on thermal processing or the application of advanced micro-thin coatings, the processes can be customised to the needs of the offshore application and the harsh working environment.

For the treatment of wear components, there is a complete family of nitriding processes. These include salt based nitro-carburising processing, which diffuses nitrogen and carbon into the metal surface, to impart wear resistance and fatigue strength. Subsequently, components may be quench-polish-quenched (QPQ) processed to improve surface finish and add an additional oxidised layer for enhanced corrosion resistance. Steel, iron and ferritic alloys can all be treated in this way.

This nitriding process is also available under several trade names including Tufftride, Tenifer, Kolene, Nu-Tride and Melonite. Unlike gas nitriding there is no need for chromium or aluminium to be present in the steel, however, where alloy steels are used high surface hardness can be achieved and increased case depths.

Alloy steel components can also be surface hardened by gas nitriding to case harden to various depths depending on the needs of the application.  This is commonly applied to steel alloys whose chemical composition contains nitride forming elements such as chromium. Gas nitriding is especially suited to the treatment of wear components in plant and machinery such as motors, pumps and compressors.

The treatment of down bore pipes and similar hollow vessels poses particular problems for offshore operators and petrochemical companies. To solve these problems Wallwork offers InnerArmor from Sub-One of California. By using plasma enhanced chemical vapour deposition (PECVD) to deposit a protective coating by gas ionisation, InnerArmor gives an even thin film of highly resistive titanium carbide or diamond like carbon (DLC) that is totally pin-hole free. Highly resistant to abrasive wear, erosion and corrosion these coatings extend plant life and provide better material flow through smoother bores and improve uptime to enhance productivity.

The company is also a specialist in high vacuum heat treatment of metal components for which they have a substantial investment in computer controlled Seco Warwick furnaces. These ensure precise time/temperature exposure to produce metal parts with a bright finish from a clean salt-free and non-oxidising atmosphere. Adaptable for use with a range of alloy steels from plastic mould steels to high speed and powder metallurgy manufactured steels, the treatment is precisely controlled to achieve customer specified hardness in very small or very large components with great consistency.

Wallwork provides a nation-wide service with 24 hour turnaround from bases in Manchester, Birmingham, and Cambridge. All locations are accredited to aerospace standards. All have fully equipped and staffed laboratories for quality assurance to validate treatments and provide documentation to certify processing to the specified standards. Accreditations include AS9100, NADCAP and ISO1400; a full list of be viewed on the web at www.wallworkht.com.