Estudo da influência de tratamentos térmicos sobre microestrutura de aços H13

Abstract

The tool steels with AISI H13 name are found in large applications in the manufacture of molds for casting, hot extrusion tools, forging dies and all kinds of dies for hot forming of work. In these manufacturing processes is of paramount importance that the steels have properties and characteristics such as resistance to deformation in the use of temperature, impact resistance, erosion resistance, creep resistance in heat treatment, good machinability and hot cracking resistance (Heat Cracking) in order to avoid failure due to plastic deformation, and the propagation of cracks by thermal fatigue. This work aims the study of different heat treatments on AISI H13 alloys used in the manufacture of hot forging dies. The motivation of this study is the low durability of national origin material compared to the foreign origin, when used in the manufacture of forging dies. In an attempt to identify the reason for this lifetime difference, we studied the influence of annealing treatment, quenching and tempering double - which are the treatments used in the production of forging dies - on the microstructure and mechanical properties of these materials. Samples of domestic and foreign origin steels were used. The characterization techniques used in the analysis of the treated samples were optical microscopy, scanning electron microscopy and hardness testing Rockwell C. were also held diffraction measurements of X-rays in order to employ the Williamson-Hall technique to estimate and microdeformations crystallite size of the treated specimens and the impulse excitation technique, analyzed from which the elastic modulus and damping modulus of these materials.