Gunter Rubig, Rübig GmbH & Co KG Interview

We are please to have an iterview with Mr. Gunter Rubig of Rübig GmbH & Co KG of Austria. When we think of Rubig we think mainly of nitriding but we are getting ahead of ourselves we will let Gunter tell us in his own words.

Gunter in light of all the recent developments in the field of nitriding I am delighted that I can ask you a few questions about RUBIG which is certainly amongst the leaders in the field. To start off how did you become involved in this industry?

“In 1986 I returned to Wels after seven years of work at BMW in Munich. Back in Austria I, my father Helmut Rübig and my brother Dr. Paul Rübig founded the first vacuum hardening service in Upper Austria. The site at Schafwiesenstrasse in Wels heat-treats tools and products not just for forges, but also for the Austrian hardware industry.”

Please give us a good idea about your company, size, history, capabilities and sales.

“Since the foundation of RUBIG in 1946, more than 70 years ago the company has grown from a small drop forging company to a center of excellence for metal processing. The unique synergy resulting from the close cooperation between RUBIG Systems EngineeringHeat Treatmentand Die Forge adds particular value for our customers. It is the knowledge and experience from all the divisions within the group that enable us to improve the performance of metal. The group employs more than 400 people who serve our customers nationally and internationally.”  

When I think of RUBIG I think of nitriding but I also know that is not your entire business. What % of your business revolves around nitriding?

“Nitriding makes the major part of our business. RUBIG is a competence center dealing with all kinds of treatments around steel and aluminum. We know how to forge, mechanically process, heat treat, coat and analyze these materials, which is unique in the branch. Nitriding makes the major part of our business.”

I know I am repeating myself when I say that nitriding is in my opinion the fastest growing heat treating process out there and yet the technology is not new. Why are so many companies investing in the technology these days?

“Nitriding and specifically plasma/ion nitriding, had quite a difficult start in the eighties. Nitriding results were not consistent and some suppliers were not reliable. It took a long time to restore the image of ion nitriding. Up to now we have been doing a lot of missionary work to highlight its advantages and its reputation is getting better and better.”

What heat treating process is nitriding replacing? Carburizing?

“It depends on the application. Nitriding – I’m talking about gas as well as ion nitriding – can of course perfectly substitute carburizing. Because of lower temperatures and therefore less distortion, hard machining after carburizing can either be minimized or even be eliminated. On the other hand, combined with a subsequent oxidation or coating process, it is also often used to replace salt bath nitriding or hard chromium coatings.”

RUBIG of course offers both gas and plasma (ion) nitriding systems. My knowledge of gas nitriding is reasonable but my knowledge of Ion Nitriding is limited. To take it one step further I have never completely understood the technology and I know I am not alone. Could you please give myself and my readers a simple explanation about Ion Nitriding?

“The principle is the same – treating steel surfaces with nitrogen. However, only nitrogen and hydrogen are used instead of ammonia. Usually, up to 700 volts are applied between the work pieces and the chamber wall. The ionization of the process gas in the processing chamber creates a glow discharge and the electric field accelerates positive gas ions towards the parts being treated.”

Ok so why one over the other? For a manufacturer what decides which technology best suited for them?

“If you know exactly what the customer’s goal is, this question is answered easily. If you have a lot of small parts to be treated around their whole surface, go for gas nitriding. Ion nitriding comes into play if areas need to be protected from nitriding, as it is much easier to achieve it technically. From a manufacturer’s point of view it’s an advantage to offer both processes in order to be independent. That’s also one of the major reasons why we have now started to actively market our gas nitriding furnaces. We have been manufacturing them for over 20 years, but were never marketing them. So customers were afraid we would push them into the direction of ion nitriding, as we were officially only manufacturing ion nitriders.
The customer’s requirements need to the priority and not the company’s preference.”

A developing trend that I see these days is vacuum nitriding. At first glance it would appear to me that this is a more expensive approach than a typical pit furnace so why use vacuum?

“Yes you are right, the vacuum furnace technology has more technological components than a gas nitriding furnace and therefore has a higher investment requirement. But with our RUBIG Competence Center we are working day by day onto increasing of the filling capacity of the machines. We are working on ideas to reduce process time without a reduction in quality. With these innovations and furnace technologies we have many proof of concept examples where parts are treated more cost effectively in a vacuum furnace than is possible with gas nitriding.”

Switching gears slightly I understand that RUBIG also does commercial heat treating. Is this a significant portion of your business? Which do you personally prefer the equipment side of things or the commercial heat treating side?

“Commercial heat treating and furnace building are of the same importance. Even if both divisions deal with heat treatment, daily business is completely different. Whereas our commercial heat treatment branches (one in Austria and one in Slovakia) are working more regionally, our furnace building division is almost exclusively doing business abroad.”

What further advancements in heat treating do you see in the near and medium future?

“The quality requirements will increase and increase, while the costs have to be decreased. For the near future it is necessary to develop more efficient heat treatment technology to overcome the cost issues. Nevertheless quality has to be the priority.”

And RUBIG – what does the future hold for your company? More commercial heat treating? Adding other technologies? Or perhaps adding more facilities around the world?

“A bit of everything. To plan the future activities is mainly dependent on the needs of our customers. We have cooperative projects regarding future technologies with our customers and universities. Regarding more heat treatment or more facilities it is like looking into a crystal ball, no one knows what will happen in five years but we are prepared for future challenges.”