A NEW PROBE TO MEASURE AND EVALUATE THE REAL QUENCHING INTENSITY BASED ON TEMPERATURE GRADIENTS

Wednesday, April 20, 2016: 2:30 PM
Ballroom C (Hyatt Regency Savannah)
Prof. Bozidar Liscic , Faculty for Mech. Engineering, University of Zagreb., Zagreb, Croatia
Prof. Bozidar Matijevic , Faculty for Mech. Engineering, University of Zagreb., Zagreb, Croatia
Dr. George E. Totten , Portland State University, Portland, OR
Dr. Lauralice de C. F. Canale , Universidade de São Paulo, São Carlos-SP, Brazil
A NEW PROBE TO MEASURE AND EVALUATE THE REAL

 QUENCHING INTENSITY BASED ON TEMPERATURE GRADIENTS

 

Bozidar Liscic1,*, Bozidar Matijevic1, George E. Totten2, Lauralice C.F. Canale3

Abstract - A new Liscic/Petrofer probe is designed measuring and record the quenching intensity in real industrial conditions.It is a cylinder of 50 mm dia-meter and 200 mm length, made of INCONEL 600, instrumented with 3 thermo-couples on the same radius of the cross-section: at 1 mm below surface, at 4.5 mm below surface,and  at the very centre of the probe. The working principle of the probe is measuring the dynamic of heat extraction, which is best represented  by the change of temperature gradients.The results of every test with this probe are presented in the form of 4 diagrams: The recorded cooling curves; The calculated heat transfer coefficient (α) as function of time; The calculated α as function of surface temperature; The calculated surface temperature with characteristic points on the temperature and on the time scale. Series of 26 tests recently performed with this probe at the Quenching Research Centre (QRC) of the Faculty for Mechanical Engineering, University of Zagreb,Croatia has shown that by using this probe distinctive differences can be documented between a mineral oil and an vegetable oil, as well as the influence of quenchant's temperature, of an antioxidative additive, and of agitation. Final conclusions of  the mentioned series of tests,confirm that:

a)The information provided, which is valuable for the practical use of a quenchant, is not obtainable from any of small laboratory probes.

b)The probe and the evaluation method are sensitive enough  to clearly differentiate the results when changes of some quenching parameters occur.

c)The Liscic/Petrofer probe can be used for different kinds of liquid quenchants, under different quenching conditions, and it is today the worldwide unique device to test,evaluate and compare their quenching intensity in industrial practice.

Keywords: Quenching; Quenching intensity measurement, vegetable oil, petroleum oil

1. Faculty for Mechanical Engineering, University of Zagreb,Croatia - bozidar.liscic@fsb.hr

bozidar.matijevic@fsb.hr *Corresponding Author

2. Department of Mechanical and Materials Engineering, Portland State University, USA –  GETotten@gmail.com

3. Departament of materials Engineering, University of São Paulo, São Carlos, SP, Brazil - lfcanale@sc.usp.br

See more of: Quenching and Quenchants II
See more of: Technical Program