Influence of the process parameters on the microstructure of a hardfacing coating elaborated by hot isostatic pressing

Abstract

Hot Isostatic Pressing elaboration of Norem02, an austenitic-ferritic hypereutectoid stainless steel, leads to the formation of an austenitic matrix with a mixture of acicular M 7 C 3 and globular M 23 C 6 carbides. The sintering tests, carried out by using an AISI 304L container, showed that the final microstructure and the carbides’ distribution of the HIPed Norem02 are strongly influenced by the process parameters (heating and cooling rate, sintering time, holding temperature and pressure) and by the particles’ size, microstructure and phase distribution of the initial powder. The morphological, crystallographic and chemical analysis of the sintered samples were completed by comprehension of the diffusion phenomena at the Norem02/304L interface, enabling the establishment of a correlation between elaboration process and final microstructure.