Evaluation of Nanosize NbC Precipitates in HSLA Steel through Microstructural Analysis and Small Angle Neutron Scattering

Haruo Nakamichi; Katsumi Yamada; Kaneharu Okuda; Toshinori Ishida; Masato Ohnuma

doi:10.4028/www.scientific.net/MSF.941.141

Paper Titles

Microstructure, Texture, Mechanical and Corrosion Performance of the Stainless Duplex Steel UNS S32205 Submitted to Warm Rolling
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Prediction of the Hydrogen-Induced Damage to Ultra-High Strength Steel Concepts
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Nucleation Effect of Ca-Oxysulfide Inclusions of Low Carbon Steel in Heat Affected Zone by Welding
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Recrystallization and Grain Growth Phenomena in Stainless Steels for Different Thermo-Mechanical Processes
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Evaluation of Nanosize NbC Precipitates in HSLA Steel through Microstructural Analysis and Small Angle Neutron Scattering
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TMP as an Effective Technique to Produce Ultra-Fine Grained Steels
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Critical Conditions of Cold Cracking in High Strength Steel Weld Based on the Local Stress Distribution and Hydrogen Accumulation
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Effect of Gap between Steel Sheet and Electrode on Resistance Spot Welding
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Effect of Coiling Temperature on the Hardening Mechanisms of a High-Ti Steel
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HomeMaterials Science ForumMaterials Science Forum Vol. 941Evaluation of Nanosize NbC Precipitates in HSLA...

Evaluation of Nanosize NbC Precipitates in HSLA Steel through Microstructural Analysis and Small Angle Neutron Scattering

Abstract:

Nano size precipitate morphologies are very important for considering the precipitate hardening mechanism of HSLA steels. Systematic analysis of precipitates from nano scale to bulk scale were carried out using Nb bearing hot rolled steels through transmission electron microscopy (TEM) observations and chemical analysis of precipitates by solvent extraction. A small angle neutron scattering (SANS) experiment was also performed using a Hokkaido Univ. compact neutron source to understand average precipitate size. Results show that both changes in hardness and the amount of precipitates (under 20nm in size) have the same tendency. Precipitate is recognized as NbC plates, which have coherency with the steel matrix by Baker-Nutting orientation relationships. A row of precipitates, formed on the interface between austenite and ferrite during transformation, is also apparent. The SANS profile shows that small size precipitate formation is detected even though the amount of precipitation is small. In addition, the magnetic scattering component of the SANS profile has high sensitivity to NbC precipitates compared with that of the nucleus scattering component. By comparing precipitate data from comprehensive experiments, we consider the relationship between precipitate behavior and the hardening mechanism.