Cooling curve analysis of an aqueous polyvinylpyrrolidone (PVP) polymer quenchant as a function of fluid velocity

Gallegos Cantu Sergio - Quaker Houghton (United States)

Cooling curve analysis is a standard methodology to evaluate quenchants products used in heat treatment industry. Polymer quenchants are sensitive to different control parameters such as concentration, polymer temperature and fluid velocity. polyvinylpyrrolidone (PVP) is a water-soluble polymer widely used to heat treat high hardenability materials and alloys, such as large forgings and castings. PVP polymers are also known for their oil-like quenching characteristics and do not exhibit inverse solubility. In this project the cooling curve analysis of a PVP polymer at 10 % of concentration was evaluated as a function of the fluid velocity. Two different methodologies were used for the cooling curves evaluation, one according to the ASTM D6482 standard method and an empirical method known as U-Tube. The fluid velocity was fixed at four different levels, 0, 0.25, 0.75 and 1.5 m/s, the measuring of the fluid velocity was at the axial direction with a water flow meter (model FM-100V5) at the quenching area of both devices. A standard probe made of Inconel 600 was used for the quenching; the probe was heated at 850 Celsius from 2 to 4 minutes of soaking time and the temperatures of the fluid were 30 and 40 Celsius; the cooling curves were calculated by the IVF SmartQuench software and the heat transfer coefficients by the IVF SmartQuench Integra software. Also, the fluid flow was simulated through Computational Fluid Dynamics (CFD), to obtain flow patterns at the cross section of the quenching devices. Finally, results were compared between both devices.