When gas quenching, the minimizing of heat treat distortion is gears may be a matter of high pressure and high velocity. That’s what Solar Atmospheres thinks, that’s why the heat treat company sends helium gas into its vacuum furnaces at more than 100mph.
Because there are diminishing returns in cooling capacity by simply increasing quench-gas pressure, increasing gas velocity might be the answer to the problem.
High pressure gas quenching has been identified as one of the most important advancements in recent developments of heat treating technology. Over the decades, an extensive amount of research and documentation has been published on the hardenability of water and oil hardening grades of steels. To date, there is relatively little or no information on the hardenability of oil hardening grades of steel quenched in a high pressure, gas environment.
High pressure gas quenching has been identified as an important advancement in heat treating technology. While an abundance of docume ntation exists on the hardenability, mechanical properties, and microstructures of water and oil-hardening grades of steel, there is relatively little or no available information on the metallurgical properties that can be achieved when these materials are quenched in a high pressure gas environment.
This article is based on a presentation at the Furnaces North America ’96 Conference, held in Dearborn, MI, September 24-26, 1996 and sponsored by Industrial Heating. In part two, partial pressure vacuum processing cycles for different materials are reviewed. Information regarding the evaporation of base metals and reactive processing was presented in the September ’97 issue of Industrial Heating.
This article is based on a presentation at the Furnaces North America ’96 Conference, sponsored by Industrial Heating. In the first part of this two-part series on partial pressure processing, techniques for controlling evaporation of base materials and reactive processing are discussed. In Part II, actual applications for production operations will be presented with full process cycles and descriptions.
A series of large cross section D2 and M2 tool steels have been obtained and cross cut prior to heat treatment. Similar heat treating, time and temperatures, will be run in a salt bath furnace and a vacuum furnace. All parts will be tracked for process temperature via deep imbedded thermocouples. Data reported, including metallurgical results, for an independent laboratory.
Moisture analysis at different phases of the heat treat process is crucial as even trace amounts of oxygen and water vapor can lead to oxidation of the materials being processed. This paper explores why moisture reduction is critical and how to properly calibrate and operate an electrolytic hygrometer to monitor moisture in vacuum heat treating.