High-cr iron rolls
The high-Cr cast iron rolls are made by centrifugal casting process, the work layer contains 12-22% Chromium. Through rational chemical composition allocations and different heat treatment, the matrix can be controlled as sorbide, troostite, bainite or martensite and certain kinds of carbides, such as Cr7C3 eutectic carbides, Cr23C6 second carbides, Mi2C carbides
etc. According to different purposes of use, the material of the core could be nodular iron or grey iron.
We make this type of rolls by centrifugal cast double poured. In this case, we can achieve an excellent wear resistance in the shell with flake graphite, bainite & martensite and primary carbide type M7C3 + secondary carbide in the microstructure. Besides the excellent wear resistance, it is also good against fire cracking thanks to the oxide film Cr2O3 formed on the body surface while rolling. At the same time, the core is strong enough to assure the roll can work safely.
The hi-Cr iron rolls are mainly used as works rolls in the roughing & previous – finishing stands of hot strip continuous rolling mills; work rolls in the roughing & finishing stands of the plate mills; work rolls in temper mills and cold strip mills; rings in the large universal mills; work rolls in the finishing stands of small section mills and bar mills.
