50 Years of Continuous Austempering

Fifty years ago this month, Bob Keough, a 45-year old engineer, banked on his previous 20 years of thermal processing equipment and heat treating experience and took an entrepreneurial risk.  With a couple of his brothers and some partners, in a former food warehouse on Idaho Street in Detroit, Michigan, he started Atmosphere Furnace Company and a commercial heat treater aptly named Controlled Atmosphere Processing Company (CAPCO).

 In March of 1962 Detroit had, perhaps, the most competitive heat treat market on the planet.  Commercial heat treaters were in great abundance.  One seasoned heat treater commented that, “In those days Detroit had a heat treat on every corner”. Bob Keough needed a niche if his businesses were to survive……so he invented one.

 Conventional quenching and tempering, carburizing and hardening, and nitriding were all well established in the area.  Austempering, however, was essentially a process that was restricted to the highest value applications.  Small, salt-to-salt processing lines (more often used for tool hardening) were the primary processing systems in use. These systems worked well for tooling and armaments, but when used for processing small, medium carbon, steel stampings the price for was prohibitive for high volume applications like automotive stampings.  Larger cast-link belt furnaces with controlled atmospheres and oil quenches were used to harden steel parts cost effectively, but these same controlled atmosphere furnaces could not be used with a molten salt quench due to the risk of explosion associated with a carbon and nitrate salt mixture. 

 Mr. Keough saw his opportunity.  He integrated a 1,500 lb/hr (680kg/hr) continuous, cast-link, atmosphere controlled furnace with a nitrate/nitrite salt quench using a clever combination of a quench curtain and a gas eductor that mitigated the risk of explosion.  Overnight, this development dropped the price for Austempering of steel stampings by an order of magnitude.  This continuous, atmosphere-to-salt process became the cornerstone of the Keough businesses and created a minor revolution in the light-weight steel stamping business.  It allowed for thin, complex stampings to be bright hardened to Bainite with little or no distortion, good ductility and resistance to hydrogen embrittlement, even at hardnesses exceeding Rc40.

 Bob Keough wasn’t done.  The continuous mesh-belt Austemper and the fully integrated batch atmosphere-to-salt (UBQA) types of equipment followed in the next two decades.  These developments have moved Austempering of steel and iron into the mainstream of thermal processing.  AFC-Holcroft, Austemper Inc., Atmosphere Heat Treat Inc. and the Applied Process family of companies can all trace their roots to these developments and they continue to innovate in Austempering.  With the introduction of the 10-ton Monster Parts™ UBQA line at AP Westshore in Oshkosh, Wisconsin, the legacy lives on.  But it all began 50 years ago in a little food warehouse in Detroit when Bob Keough took a risk and acted on an innovative idea.