ISSN:
1013-9826
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:
In order to improve surface properties, high chromium austenitic base heat-resistant caststeel was scanned with a 5kW continuous wave CO2 laser, the specimen was aged at the temperatureof 600°C~900°C. The microstructure and phase composition of the specimen were analysed withoptical microscopy, electronic microscope and X-ray diffractionse. The hardness was measured. Theresults show that as-cast structure of high chromium cast steel is coarse and non-homogeneous, andmainly consist of austenite, ledeburite and carbides. After laser surface melting, the section is dividedinto the melted zone consisted of fine austenite and carbides, the heat affected zone composed ofaustenite and eutectic carbides, and the base meta1. The melted zone is very fine structures withdendritic crystals, only at the bottom a cellular structure is observed. A continuous carbide network islocated in the austenitic grain boundaries at the heat affected zone. Carbides particles distributedispersed out, the hardness of melted zone increases 35% than the base metal after aging. The areaand the hardness of various zones are related to the laser processing parameters. The hardening depthof melted zone and heat affected zone may be up to 200μm~300μm
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/57/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.373-374.416.pdf
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