Stress relieve in molds manufacturing of AISI 420 steel

Resumo

This work consists in a case study to show the correct procedures for heat treatments for general steels, comparing the results using a correct procedure to stress relieve and an incorrect procedures. For this experiment were made four samples using the commercial martensitic stainless steel, that is normally used to construct cavities for plastic injection molds. The geometry used for samples is defined trying to simulate a cavity of a plastic injection mold. Between the four samples, one was produced with final dimensions and submitted to the quench treatment. Other three samples were produced with an intermediates dimensions and submitted to a stress relieve treatment and only after this treatment, the samples were finished and submitted to a quench treatment. Comparing the results is possible to analyze that the sample submitted to the corrects procedures to execute the stress relieve heat treatments presented the small deformation after the quench treatment and in the sample that weren’t realized the normalization intermediate treatment presented the biggest deformation and the other two samples presented intermediate deformations. The conclusion is that necessary to use the intermediate normalization treatment for stress relieve from works with tool machine to avoid damages in the cavities of plastic injection molds.