S19  Usinagem dos Materiais    Titulo: INFLUENCE OF CRYOGENIC TREATMENT ON THE PERFORMANCE OF HSS TOOLS   Resumo : M2 HIGH SPEED STEEL TOOLS AFTER CONVENTIONAL HEAT TREATMENT WERE SUBMITTED TO DEEP CRYOGENIC TREATMENT. IT CONSISTS IN SUBMIT THE TOOLS TO EVAPORATING LIQUID NITROGEN ATMOSPHERE, AT TEMPERATURES OF THE ORDER OF -190°C DURING A PERIOD FROM 20 TO 60 HOURS. STUDIES IN CRYOGENIC TREATED STEELS HAVE SHOWN A DECREASE IN THE AMOUNT OF RESIDUAL AUSTENITE AND PRECIPITATION OF ULTRAFINE CARBIDES. SOME RESEARCHERS HAVE CONCLUDED THAT THIS TREATMENT CAN INCREASE TOOL LIFE. THERE ARE SOME CONTROVERSIES AND DOUBTS ABOUT THIS SUBJECT, HOWEVER. THIS HAS ENCOURAGED THIS WORK. MACHINABILITY TESTS IN M2 HSS TOOLS TO VERIFY THE CRYOGENIC TREATMENT INFLUENCE WERE CARRIED OUT. IN EACH TEST THE PERFORMANCE OF THE CONVENTIONAL HEAT-TREATED TOOL WAS COMPARED TO THE CRYOGENIC TREATED ONE. MICROSTRUCTURE, HARDNESS AND MICROHARDNESS BEFORE AND AFTER CRYOGENIC TREATMENT WERE DETERMINED AND ANALYZED. ABRASIVE WEAR RESISTANCE AT THE TOOLS IN SPECIFIC TESTS WERE ALSO STUDIED . ALL OF THEM AD THE OBJECTIVE TO COMPARE PROPERTIES. ALTHOUGH HARDNESS AND ABRASIVE WEAR TESTS DID NOT SHOWED CONSPICUOUS DIFFERENCES, THE CRYOGENIC TREATED TOOLS OUT PERFORMED THE NON TREATED ONES IN MACHINABILITY TESTS. KEY WORDS : HIGH SPEED STEELS TOOLS, CRYOGENIC TREATMENT, ABRASIVE WEAR, MACHINABILITY.     Autores : Franco, Sinésio Domingues Junior , Antônio Maria de Souza Machado, Álisson Rocha Silva, Flávio José da     Trabalho Completo :   COBEM99 | Comissão  Organizadora | Palestras | Sessões Técnicas | Autor | Simpósios e Sessões Especiais | Revisores |  Título  dos  Trabalhos | Local