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:
A tough hypereutectic high chromium white iron has been developed by considering thealloy as a double in-situ fibrous composite and applying the principles of composite theory. Theeutectic in the ternary Fe-Cr-C system solidifies as M7C3 carbide rods of irregular hexagonal crosssection in a matrix of austenite. The carbide rods are intermittently joined together with nomisorientation at the joint. The colonies (eutectic grains) of a 27%Cr alloy solidify with a flat solid– liquid interface. In hypereutectic high chromium white irons the primary carbide solidifies assingle crystal rods with no branching. Depending on the thermal conditions in the mould theprimary carbides are nucleated only on the mould surface, or repeatedly at the solid – liquidinterface. In 27% Cr, 4.5%C hypereutectic alloys, the as-solidified microstructure is one of longparallel aligned primary carbides in a eutectic matrix of carbide rods in austenite, or short randomlyorientated primary carbides in a eutectic matrix. In either case the microstructure can be describedas a double in-situ fibrous composite. The application of composite theory has resulted inhypereutectic high chromium white iron castings with improved fracture toughness similar to thatof heat-treated alloy steel but with superior wear resistance
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/40/transtech_doi~10.4028%252Fwww.scientific.net%252FAMR.32.111.pdf
Permalink