Actas de congresos
Hot tensile behavior and fracture characteristics of a plasma nitrided maraging 300 steel
Fecha
2017-01-01Registro en:
Materials Science Forum, v. 899 MSF, p. 436-441.
0255-5476
10.4028/www.scientific.net/MSF.899.436
2-s2.0-85027372053
6407308739122149
0000-0001-6465-4538
Autor
Universidade Estadual Paulista (Unesp)
Instituto de Pesquisas Energéticas e Nucleares
Universidade Federal de São Paulo (UNIFESP)
Instituto Tecnológico de Aeronáutica
Instituto de Estudos Avançados
Universidade Presbiteriana Mackenzie
Instituto de Aeronáutica e Espaço
Institución
Resumen
The influence of plasma nitriding of a maraging 300 steel on mechanical properties at high temperature has been studied. Samples were tensile tested at 600°C in four conditions: solution treated (MAR-S), solution treated and aged (MAR-SA), solution treated and plasma nitrited (MAR-SP) and solution treated, aged and plasma nitrited (MAR-SAP). In the same sequence, the yield strength and ultimate tensile strength increased slightly respectively from 1073 to 1189 MPa and 1174 to 1301 MPa, an increase of about 10% due to plasma nitriding. All the samples presented similar values of elongation, around 18%, but the cross section area reduction decreased significantly by plasma nitriding from ~70% for MAR-S and MAR-SA to ~45% for MAR-SP and MAR-SAP, that is an decrease of 36% in average. This decrease is attributed to brittle fracture nucleated at 50 µm thick iron nitride layer. The inner fracture surface of the tensile tested specimens was predominantly ductile presenting characteristic microcavities.