| Full text | |
| Author(s): |
Cesar Augusto Duarte Rodrigues
[1]
;
Luiz Carlos Casteletti
[2]
;
Frederico Augusto Pires Fernandes
[3]
;
Carlos Alberto Picon
[4]
;
Germano Tremiliosi-Filho
[5]
Total Authors: 5
|
| Affiliation: | [1] Universidade de São Paulo - USP. Instituto de Química de São Carlos - Brasil
[2] Universidade de São Paulo - USP. Departamento de Engenharia de Materiais e Manufatura - Brasil
[3] Universidade Federal do ABC - UFABC. Centro de Engenharia, Modelagem e Ciências Sociais Aplicadas - Brasil
[4] Universidade Estadual Paulista Julio de Mesquita Filho - UNESP. Campus de Ilha Solteira. Departamento de Física e Química - Brasil
[5] Universidade de São Paulo - USP. Instituto de Química de São Carlos - Brasil
Total Affiliations: 5
|
| Document type: | Journal article |
| Source: | REM, Int. Eng. J.; v. 77, n. 4 2024-09-06. |
| Abstract | |
Abstract The aim of this study was to verify the pitting corrosion behavior in the surface layers obtained by plasma nitrocarburizing at 400 and 450 °C/5 h on two types of super-martensitic stainless steel, namely micro-alloyed (Nb-SMSS) and unalloyed (SMSS). The results reveal that in all the nitrocarburized layers, a discontinuous, thin layer measuring less than 5µm in thickness exhibits a microhardness exceeding 950 HV0.05, for the two steels. Furthermore, the structure of the surface layer is a combination of expanded austenite (γN), expanded martensite (α`N), ε-Fe2-3N, cementite (θ-Fe3C), and traces of CrN. The surfaces exhibit poor corrosion resistance across all layers, which can be attributed to localized micro-galvanic corrosion between the iron nitride (ε-Fe2-3N) and expanded austenite (γN), since they are known to have higher corrosion resistance, as well as expanded martensite ((α`N) and cementite (θ-Fe3C), which have lower corrosion resistance. This corrosion process initiates after the dissolution of the surface layer in a 3.5% NaCl solution, subsequently leading to substrate corrosion. (AU) | |
| FAPESP's process: | 19/22183-6 - Electrocatalysis VI: fundamental and applied aspects of emerging and classical problems in electrochemical energy conversion |
| Grantee: | Edson Antonio Ticianelli |
| Support Opportunities: | Research Projects - Thematic Grants |