ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
The nitriding process is one of the common methods for surface hardening, and consists of heattreatment in a furnace for many hours. The nitriding behavior and strengthening mechanism of Ti addedsteels in the nitriding process, which is applicable to a high temperature and rapid process such as thecontinuous annealing of steel strip, were investigated.The sheets were hardened only near the surface. The hardening of the surface layer is due to the formationof clusters or fine precipitates with disc-like shape consisting of titanium and nitrogen. The maximumhardness depends on the content of Ti in the steel while the annealing time and the concentration of NH3influence the depth of the hardened zone affected by nitriding. It is thought that the hardening only nearsurface improve bending stiffness without significant increase of yield stress. So there is a possibility that thesurface hardening improves the dent resistance of automobile outer panels without significant worsening ofthe surface deflection.To study these behaviors theoretically, a model for predicting the precipitation behavior due to nitriding hasbeen developed. The experimental results can be reasonably explained by the model calculations. And also,the estimation of the amount of strengthening was carried out. It indicated that the strengthening mechanismis mainly the precipitation hardening of TiN that could be Ti nitrides or Ti-N clusters
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/15/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.539-543.4179.pdf
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