Kinetics of Reverted Austenite in 18 wt.% Ni Grade 300 Maraging Steel: An In-Situ Synchrotron X-Ray Diffraction and Text
- PDF / 4,550,557 Bytes
- 11 Pages / 593.972 x 792 pts Page_size
- 106 Downloads / 179 Views
https://doi.org/10.1007/s11837-020-04254-w 2020 The Minerals, Metals & Materials Society
INTERFACIAL STABILITY IN MULTI-COMPONENT SYSTEMS
Kinetics of Reverted Austenite in 18 wt.% Ni Grade 300 Maraging Steel: An In-Situ Synchrotron X-Ray Diffraction and Texture Study ´ RESˇ,1,2 ˜ O DOS SANTOS ,1,7 MILOSLAV BE LUIS PAULO MOURA 1 MIRELA OLIVEIRA DE CASTRO, PAULO WILLIAN CARVALHO SARVEZUK,3 LEONARDO WU,4 ´ VIO GASPAR HERCULANO,1 ANDREA PAESANO JR.,5 LUIS FLA CLEITON CARVALHO SILVA,1 MOHAMMAD MASOUMI,6 and HAMILTON FERREIRA GOMES DE ABREU1 1.—Department of Metallurgical and Materials Engineering, Federal University of Ceara´, Campus do Pici, Av. Humberto Monte, Fortaleza, CE 60445-554, Brazil. 2.—BIOFABRIS - National Institute of Science and Technology in Biomanufacturing, Faculty of Chemical Engineering, University of Campinas, Av. Albert Einstein 500, Campinas, SP 13081-970, Brazil. 3.—Department of Physics, Federal Technological University of Parana´, Via Rosalina Maria dos Santos, Campo Moura˜o, PR 87301-899, Brazil. 4.—Brazilian Center for Research in Energy and Materials - CNPEM, R. Giuseppe Ma´ximo Scolfaro 10000, Campinas, SP 13083-970, Brazil. 5.—Department of Physics, State University of Maringa´, Av. Colombo 5790, Maringa´, PR 87020-900, Brazil. 6.—Center of Engineering, Modelling and Applied Social Sciences, Federal University of ABC, Av. dos Estados, 5001, Santo Andre´, SP 09210-580, Brazil. 7.—e-mail: [email protected]
In this study, we investigated the transformation kinetics of martensite fi reverted austenite in 18 wt.% grade 300 Ni maraging steel. The kinetics was evaluated based on the in situ synchrotron x-ray diffraction data collected during isothermal heat treatment at 570C. The onset of transformation martensite fi reverted austenite was detected after 5 min of aging. The austenite fraction increased as a function of annealing time and reached approximately 30 vol.% after 3 h of heat treatment. The electron backscatter diffraction technique revealed that reverted austenite is formed preferentially on both the martensitic lath boundaries and sub-grain boundaries inside the laths, in particular in those with high Taylor factor values. The reverted austenite maintains an orientation relationship with the prior austenite; however, variant selection can take place.
INTRODUCTION Precipitation-hardened martensitic high-strength maraging steels are primarily employed in aircraft, aerospace, tooling and power generation applications.1–4 After hot working, the steel is usually solution annealed at a temperature > 800C followed by cooling to room temperature to produce a soft martensitic matrix. Then, the material is subjected to aging heat treatment typically at 480C, which leads to precipitation of fine dispersed particles. Various types of precipitates, such as Ni3Mo, Ni3Ti, Fe2Mo and Fe2Ti, can precipitate during the aging.1 During the early stages of aging
treatment, mainly Ni3(Ti,Mo) and Fe7Mo6 are formed.2–4 If the steel is aged at higher temperatures of 550C (below Ac1 temperat
Data Loading...
