ISSN:
1662-8985
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:
High strength multiphase CMnSi steel is increasingly used in passenger cars. Si and Mn alloyinglevels are typically in the range of 1-2% in mass. While Si improves the mechanical properties, itconsiderably deteriorates the galvanisability of steel. Residual water vapour in the reducing gasatmosphere during the intercritical or austenitic annealing results in the selective oxidation of Si andMn at the steel surface. Besides Mn and Si, C is oxidized as well at the steel surface, leading to theformation of CO gas and decarburisation of the steel surface. This decarburisation has a majorinfluence on the phase composition in the steel surface region: it shifts the ferrite to austenitetransformation to higher annealing temperatures, leading to differences in surface and bulkmicrostructure. The phase composition influences the solubility and diffusivity of all alloyingelements near the surface. The evolution with temperature of the selective oxidation at the steelsurface has been studied by interrupted annealing in a protective atmosphere containing residualwater vapour. The influence of the annealing temperature on the selective oxidation of Mn and Si ischaracterized by XPS (X-ray Photo-electron Spectroscopy) analysis
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/39/transtech_doi~10.4028%252Fwww.scientific.net%252FAMR.15-17.129.pdf
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