Chrome - Don’t write the Obituary too soon

Published: 5th December 2013 | Issue 27

Hexavalent Chrome – still extensively and effective used in industry today

It is becoming increasingly fashionable, almost politically correct, to be seen to be calling time on a material that has served us well in the past, continues to serve us in the present and will go on into the future for many years until that, as yet unknown, alternative becomes available. I refer, of course, to Chromium metal. At this stage I have to say, to paraphrase the old adage, “Rumours of [its] death have been greatly exaggerated”.

Chrome has numerous well known properties which have been practically proven over many years – these include wear & abrasion resistance, corrosion resistance and significantly improved lubricity over an uncoated material. I would even say that our own brand of Chrome, Armoloy NTDC can offer substantial benefits over ordinary chrome but that is another area for discussion.

As is common knowledge, hexavalent Chrome is among the list of products included in the SVHC list produced by ECHA, the European Chemicals Agency. The SVHC list comprises of chemicals or Substances of Very High Concern. Whether or not you agree that hexavalent Chrome should be on that list is an argument that is currently the subject of certain legal processes across Europe. Nevertheless, it has to be recognised that hexavalent Chrome is currently on the list.

However, and this is where much of the misrepresentation is rooted, REACH does not seek to ban hexavalent Chrome; it just seeks to regulate it as long as it continues to be the best available option because no other equivalent has been readily identified.

Is it so unreasonable to want to restrict the use of any chemical that can be readily substituted by another, less harmful variety? Is this not a crucial part of the ‘Duty of Care’ that we all sign up to in the Health & Safety at Work act? All of this falls under standard procedures under COSSH and Risk Reduction analyses. Surely, it is in the interest of all of us to want to minimise the presence of hazardous chemicals, not only in the workplace but as a general principal of safeguarding the environment? Is it wrong to want to see regulations that offer a long term safeguard for all of us?

At Aromloy we readily accept that hexavalent Chrome is not a pleasant substance and that the term toxic suits it very well. We also accept the proposal that it be eliminated, where possible, from coatings that were deposited in the hexavalent state, i.e. certain Chromate passivation finishes were a crucial move in improving the contact environment, certainly in the automotive industry. I can also follow the logic that says, where trivalent Chrome has apparently proved to be an effective alternative as in the decorative chrome industry, then, if this is shown to be correct, the less injurious form should be substituted at the earliest opportunity.

But, and here is the big but, what if an effective alternative is not available? Engineering Chrome, Hard Chrome or our own Armoloy Nodular Thin Dense Chrome cannot be deposited from trivalent Chrome. Certainly in our case and, to the best of our knowledge in the other examples of engineering Chrome, the chemical process is inextricably bound with the hexavalent form of Chromium. We would also add that, if properly processed, the final Chrome coating is virtually chemically inert and can be certified as safe for use on Food, Pharmaceutical and Medical equipment. Again, referring back to our own product, Armoloy NTDC - this has been adequately tested for toxicology and biocompatibility and also approved for use in high radiation nuclear environments. Certainly, there is NO REACH liability for Downstream users.

You may ask ‘is there no equivalent of this material or even an acceptable alternative’? Well, our answer is ...not entirely. Scientists, both civilian and military, have been searching and testing for years and it is claimed that alternative processes are known and are available.

We think not. These potential alternatives have included thermal spray plasma coating, alternative chemical processes (note that both Nickel and Cobalt salts are on the REACH agenda), explosive bonding and vacuum chamber processes.

We are not aware of any other process that has both the overall versatility of Chromium and combines its simultaneous advantages of hardness, corrosion resistance and lubricity in a single coating. Certainly, a number of alternatives claim to be as effective as Chromium and, in certain areas, there is no doubt that they can be employed advantageously and, in niche applications, may well be superior.

However, have you ever seen a vacuum chamber three metres, four metres or even five metres long? Do you consider 480 – 500 degrees Centigrade as a low temperature process? Will your alternative process keep your components well below the boiling point of water during coating but function in service from – 200 Centigrade to + 700 Centigrade? Can the process be applied to finished tolerances of +/- 1 micron in Critical areas thus avoiding costly re-machining after coating?

Ultimately, the customer will decide on the viability of the alternative processes and, here at Armoloy UK, we have ultimate confidence in the package that we can offer.

As far as future restrictions go, we have no problems with a tightening of controls. We have all seen the pollution and habitat wastage that result from unregulated processes. We welcome a level playing field for all processors where the same standards of pollution control and working conditions are applied to all. As a Gold Subscriber member of REACHREADY, we are continually familiarising ourselves with the legislative deadlines and relevant hurdles that we are required to clear.

Our Process and Quality control systems are fully accredited to ISO9001, AS9100 and NADCAP. Our current aerospace projects include the Airbus A380 airliner, the Airbus Military A400M airlifter, the Boeing 787 airliner and the F35 joint strike fighter which are all scheduled to run well past 2030.

There is no doubt that beyond 2018, under the current proposed legislation and full implementation of REACH, the Chrome plating industry will be irrevocably changed. It is possible that some companies will remove Chrome from the range of treatments they offer. The new regulations will certainly require a significant investment for those who are inextricably tied to the industry but in no way does that mean that the product will disappear.

Yes - there is a continuing significant future for engineering Chrome and we at Armoloy(UK) intend to be an important part of it.

Armoloy (UK) Ltd
Tel: 01902 310375
www.armoloy.co.uk

Armoloy (UK) Ltd