Craftsmen working with precious metals?

With the price of nickel hitting US $1 per ounce Alan Brown of Arc Energy Resources argues that weld overlay cladding specialists should be reclassified as craftsmen working with precious metals.

Craftsmen working with precious metals With the price of nickel hitting US $1 per ounce Alan Brown, Sales Director for Arc Energy Resources, argues that weld overlay cladding specialists should be reclassified as craftsmen working with precious metals.

In January 2007, following a 160% price rise in 2006, nickel became the first base metal to break US $1 per ounce as prices surged to another record high.

The units of US dollars per ounce are typically used when quoting prices of precious metals such as silver and gold, and although it's not likely that nickel will be used in jewellery, the news does put the price of this so-called commodity metal into perspective.

As analysts predict further gains, it is worth noting that about two-thirds of world nickel production goes into stainless steels, which are commonly used to produce corrosion resistant components for, among others, the oil and gas industry.

Duplex steels and nickel based alloys are the only materials in general production which, when welded, can match the strength of carbon steels.

However, with growing demand from the new manufacturing economies of India and China, cost and availability are beginning to cause serious concerns for manufacturing companies.

The cost aspect is particularly relevant where large quantities of pipe and fittings are needed or when large forgings or castings, such as wellhead valve systems and pipe bundle bulkheads, are to be used.

So, where complete corrosion protection is required it makes economic sense to manufacture the component in a cheaper material and overlay clad with a corrosion-resistant alloy, rather than manufacture the whole component in a more expensive, highly alloyed material.

The use of carbon and low alloy steels clad with a corrosion resistant alloy is a recognised and proven cost saving technology that has been established in the oil and gas industry for some years and is expected, with the increasing cost of nickel and other metals, to remain an economical and technical alternative to solid alloys.

So will the industry's perception of weld overlay cladding specialists such as Arc Energy Resources be elevated to the status of craftsmen working with precious metals? It's unlikely.

The overwhelming advantage of weld overlay cladding is its versatility.

Whatever the shape or size of the pipe or component there is a process that can be applied; and whatever the medium there is an alloy to counteract its corrosive or abrasive properties.

Where maximum protection is needed corrosion resistant alloys (CRAs) such as austenitic (300 series) stainless steels, ferritic/martensitic (400 series) stainless steels, duplex stainless steels or the more complex high nickel chromium alloys must be considered.

Yes, they are all affected by the elevation of nickel to "precious metal" status, but their application as a cladding material does reduce the impact of rising costs, while providing the assurance of a heavy-duty metallurgically bonded protective layer that will not be undermined or dislodged in service.

This is especially relevant for pipe systems where weld overlay cladding can be applied specifically to areas under attack, for example where a directional change of flow takes place at a bend or diversion point, or where the medium is physically propelled by pumping or other means.

It is also true when weld overlay cladding is used to protect oilfield valves from corrosion.

As oil and gas wells are sunk deeper and produce hotter and more aggressive "cocktails" of corrosive media, equipment manufacturers are forced to specify highly alloyed materials for valves and associated components to overcome the inevitable corrosion problems.

The alloys used to manufacture the valves and associated components include carbon and low alloy steels through to stainless steels.

And all can be overlay clad to provide additional corrosion resistance in specified areas or indeed over all surfaces in the case of the carbon and low alloy varieties, to ensure total resistance.

And even when repairing equipment, affected areas can in many cases be pre-machined and, using automated weld overlay cladding or specialised manual welding, rebuilt with a CRA such as complex nickel aluminium bronze.

Typically, the repair will be superior to the original metal.

Despite the huge hike in price it's still difficult to think of nickel as a precious metal but it shouldn't be quite so hard to think of weld overlay cladding specialists as craftsmen.

Arc Energy's Managing Director has over 25 years experience in the industry, is qualified as a Chartered Engineer, an MSc in welding engineering, a European Welding Engineer and European Engineer.

The qualifications of other key employees include a BSc in mechanical engineering, a Masters Degree in quality assurance and 30 years experience and a specialised knowledge of corrosion resistant alloys.

Teams of welders and fabricators are trained to the highest standards and qualified to specifications that include ASME, BS EN287 and NES706.

A wide range of base metal/cladding combinations has been qualified to ASME, API 6A and NACE.

The manufacturing infrastructure is also qualified to BS ISO9001:2000.

I rest my case.

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