Vacuum heat treating modified tool steels having reduced silicon content and better cleanliness using the latest vacuum furnace technology achieves uniform properties and minimizes distortion.
The use of vacuum furnaces to heat treat dies for the die-casting industry in the 1980s and 1990s had primary objectives of reducing distortion and obtaining a nice surface finish with no post cleaning combined with easy process control. Minimizing distortion saved money on post machining, especially on large H13 hot-work tool steel die inserts. The downside was that low distortion was mostly realized through a very slow gas quench (The North American Die Casting Association (NADCA) and many leading companies in the die casting industry issued several papers with the recommendation of a minimum surface quench speed of 50 F/min (28 C/min). Through the selection of high quality die material and the best heat treating sources together with the creation of heat treat specifications like GM Powertrain's (GMPT) DC-9999-1 in 1995 and Ford's AMTD DC2010 in 1999, the North American automotive industry saved millions of dollars in die costs.