Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
Study of the heat transfer during the quenching of a Hadfield steel in polymeric solution
Submission Author:
Ana Paula Dias Carvalho Pereira , SP
Co-Authors:
Ana Paula Dias Carvalho Pereira, Renata Neves Penha
Presenter: Ana Paula Dias Carvalho Pereira
doi://10.26678/ABCM.COBEM2021.COB2021-1850
Abstract
Hadfield steels or manganese steels are used in functions that require very high mechanical strength and toughness, such as in jaw and rotary applications in primary ore crushing. The demand for this type of material is high mainly in the railway and mining industries, as this steel has a unique combination of high toughness, high impact resistance, excellent cold workability and wear resistance. Considering the important participation of the mining industry in the Brazilian economy, the technological relevance of this work is justified. The quenching of this steel is traditionally carried out in water, which guarantees high cooling rates, but not uniform, which results in very high residual stresses, which can reduce the service life of the tempered components. However, it is known that the use of polymeric solutions as a quenching medium also exhibits high rates of heat removal and allows for more uniform cooling, since the vapor layer breaks instantly. The objective of this work is to simulate the heat transfer, by calculating the heat transfer coefficients using the regular thermal method. Following the parameters of ASTM D6200, cooling curves were obtained in 8 and 10% PAG solution. The temperature variation over time is the boundary condition used in the regular thermal method to obtain the heat transfer coefficients at the interface of the metal and the quenching medium. What is intended to be determined is whether the difference between cooling speed in these concentrations of PAG changes the percentage of martensite after quenching. The amount of martensite will also be calculated using the Koistinen-Marburguer ratio.
Keywords
quenching, Polymer quenchant, Heat transfer coefficient, Hadfield steel
