Quenching with fluid jets

Abstract

The quenching process within the heat treatment of workpieces can be optimized by applying locally adapted quenching conditions. Locally variable heat transfer conditions at the workpiece surface are realizable by impressing and regulation of adjustable flexible flow fields on the basis of arrays for jet flow impingings on surfaces inside the quenching media. With use of these adapted jet fields it is possible to generate spatially and or timewise varying quenching conditions with high cooling intensities for a systematic locally heat transfer during the quenching process.For the analysis of workpiece distortion activated by heat treatment, the heat transfer and hardening process by quenching in adapted flexible flow fields is modelwise described. By controlled quenching with liquid media, the quenching intensities can be increased for specific local hardening results on massive workpieces. By that, the heat treatment process and the quenching result can be affected and optimized by controlling the boiling process and the establishing of the rewetting front on the workpiece surface.Key words: distortion, distortion compensation, distortion engineering, jet quenching, impinging jet

In-process distortion measurement during a gas quenching process through digital speckle photography

“…This in turn facilitates (1) compensation of distortion potential through spatially and/or time wise varying flexible flow fields and (2) specific experimental analysis of workpiece distortion in heat treatment e.g. under highly symmetric quenching conditions [6].…”

“…individual engine components. In the framework of the Collaborative Research Center (SFB 570) ''distortion engineering'' [5] in Bremen, a special quenching technology in gaseous media has been developed for the analysis and model wise description of the hardening process for simple workpieces such as rings and shafts [6]. An advantage of gas quenching compared to liquid quenchants (oil, water, and aqueous polymers) is that quenching with gas proceeds more uniformly, minimizing residual stresses and distortion [7].…”

Process integrated distortion compensation of large bearing rings

“…Specimens showing a triangularity of 155 lm were quenched using an 1 Foundation Institute of Materials Science/Stiftung Institut für Werkstofftechnik (IWT), Badgasteiner Straße 3, 28359 Bremen, Germany, 2 Rothe Erde GmbH, Tremoniastraße 5-11, 44137 Dortmund, Germany asymmetric gas nozzle set-up. The shape deviation could be reduced to 77 lm [2].…”

“…Specimens showing a triangularity of 155 lm were quenched using an 1 Foundation Institute of Materials Science/Stiftung Institut für Werkstofftechnik (IWT), Badgasteiner Straße 3, 28359 Bremen, Germany, 2 Rothe Erde GmbH, Tremoniastraße 5-11, 44137 Dortmund, Germany asymmetric gas nozzle set-up. The shape deviation could be reduced to 77 lm [2]. Due to the relatively low heat transfer coefficients in gas flows the use of turbulent liquid jets is necessary to enable both higher heat transfer rates and distortion compensation potential when larger specimen's cross sections are to be quenched.…”

Numerical Study of Laminar Confined Impinging Slot Jets with Nanofluids

“…Several studies have been developed on impinging air jets [1,2] but liquid jets have been recently studied because they have possible application to the cooling of heat engines [5,7], thermal control in electronic devices [8,9], and the thermal treatment of metals and material processing [10][11][12].…”