In the aircraft industry, heat treatment is performed that has to conform to several specifications and monitoring the performance of a quenchant is one aspect that must be taken into account. However, most of the accepted methods in these specifications, (i.e., Jominy test, magnetic quenchometer tests) have come under criticism recently and in some cases have been shown not to provide the sensitivity that is required. The ISO 9950 Inconel probe system for characterizing the cooling rate of quenching oils has received considerable attention over the past several years. This paper describes four years’ experience using the Inconel probe test as a quality control tool to monitor the cooling characteristics of a quench oil used in production. Preliminary testing of the system was carried out to ensure that it was sensitive to the characteristics and contaminants being looked for and these are described together with relevant results from routine testing of a production oil quenchant.
San Pedro, R.I., Owens, S., Wallis, R. A., “Four Years’ Experience Using an Inconel Probe to Test the Cooling Characteristics of Production Quench Oil,” 17th Heat Treating Society Conference, Indianapolis, IN, September, 1997.