Microstructural Evolution in 36%Ni Austenitic Steel during the ARB Process

Bo Long Li; Nobuhiro Tsuji; Yoritoshi Minamino

doi:10.4028/www.scientific.net/MSF.512.73

Paper Titles

Microstructural Evolution during Simple Heavy Warm Deformation of a Low-Carbon Steel
p.49

Effect of Hydrogen on the Fracture Behavior of High-Strength Cr-Mo Steel
p.55

Evaluation Method for Fracture Mechanics-Based Material Toughness from Charpy Impact Test
p.61

Temperature and Orientation Dependence of Fracture Behavior of Directionally Solidified Duplex-Phase Crystals Composed of Ni₃X-Type Intermetallic Compounds
p.67

Microstructural Evolution in 36%Ni Austenitic Steel during the ARB Process
p.73

Fine-Grained Structure Formation in 7475 Al Alloy during Hot Multidirectional Forging
p.79

Tensile Deformation Behaviors of Ultrafine Grained Al-Fe-Si Alloy Sheets
p.85

EBSD and TEM Characterization of Ultrafine Grained High Purity Aluminum Produced by Accumulative Roll-Bonding
p.91

Acetate and Chloride Effects on Hydrogen Production across Crevices
p.97

HomeMaterials Science ForumMaterials Science Forum Vol. 512Microstructural Evolution in 36%Ni Austenitic...

Microstructural Evolution in 36%Ni Austenitic Steel during the ARB Process

Abstract:

A 36mass% Ni austenitic steel was deformed to equivalent strains of 0.8 to 4.8 by the accumulative roll-bonding (ARB) process at 500°C, with slight lubrication. We analyzed the microstructure and crystallographic analysis by employing the electron back-scatter pattern (EBSP) technique in a field emission gun (FEG) SEM. After several ARB cycles, ultrafine lamellar boundary structures elongated in the rolling direction (RD) formed uniformly in the material. Observations indicated that the mean spacing of high-angle lamellar boundaries determined from the EBSP results decreased exponentially as a function of equivalent strain. The fraction of high-angle boundaries (HABs) increased, thus the average misorientation of the boundaries increased with increasing strain. In the six-cycle ARB-processed specimen, the mean spacing of the uniform lamellar boundaries was 150 nm, the fraction of HABs was 75%, and the average misorientation was 32°. The ultrafine lamellar boundary structure in the 36%Ni austenitic steel was finer and straighter than in ferritic steel (IF steel) deformed under similar conditions, probably because recovery occurs more easily in ferritic steel than austenitic steel.