Resumo:
This work presents the development of a project for the prediction of microstructural
properties and phase transformations in the hardenability process of ASM 1045 Steel. The
developed procedure mixes numerical simulation, advanced through a computational routine
carried out in free code and an experimental analysis, to verify the results. The mathematical
model applies concepts of numerical methods, heat transfer, phase transformation and TTT
diagrams, to simulate the Hardenability phenomenon as a function of the cooling rate, including
the addition of heat due to the phase change. For the experimental stage, the design and
construction of an automated and instrumented Jominy test machine was developed, which aims
to be a contribution tool to reinforce the study of alloy steels, in addition to obtaining cooling
curves through tests with bodies standardized SAE 1045 steel test samples; The equipment was
built to perform tempering tests on samples governed by ASTM A255 2002; where its function
is to characterize the hardenability of steels. First, the equipment structure was built using a
structural angle and ASTM A-36 steel sheet, which created a rigid structure to support other
elements of the equipment. The equipment has a fast clamping and transport device between
the oven and the cooling system, which has a sample fixation and centralization element that
guarantees correct vertical positioning in the water outlet hole, so that cooling occurs
exclusively in the lower sample base; It was essential to find the most appropriate way to adapt
the oven, the transport device and the refrigeration device, also facilitating their operation.
Aiming to obtain different cooling rates throughout the specimen, instrumentation with specific
characteristics was designed to meet temperature monitoring. After cooling, the specimen was
subjected to hardness, microhardness and metallography tests to characterize the
microstructures obtained and the variation in mechanical properties for different cooling rates;
in this way, it is possible to obtain analysis and hardenability results to compare with numerical
simulation data.
