Effect of Powder Particle Sizes on the Development of Ultra Hard Surface Through Superplastic Boronizing of Duplex Stainless Steel

Abstract

In this work, a further study on boronizing using compression method called superplastic boronizing (SPB) was conducted. This process was conducted on duplex stainless steel (DSS) which has been thermo-mechanically treated to obtain fine grain microstructure and exhibit superplasticity. Effort was being put in obtaining ultra hard surface through SPB by focusing on the boron powder particle size. The microstructure, hardness, and layer thickness of the boronized materials were investigated. The formation of hard boride layers were confirmed by XRD analysis. Metallographic studies and scanning electron microscope (SEM) revealed a uniform, dense and smooth morphology of boride layer produced on all the boronized specimens. Comparison using as-received DSS with coarse microstructure also was performed. The overall results from the study showed that the SPB process can produce a very hard surface and significantly improve the surface properties of DSS.

Boronization and Carburization of Superplastic Stainless Steel and Titanium-Based Alloys

“…The XRD pattern of the boronized SPDSS is shown in Figure 13 . This diffraction pattern indicates the generation of Cr boride and Fe boride [ 15 , 16 ]. From this result, very high hard surface will be expected.…”