- Abrasion-Resistant White Cast Iron 2
1.1 Chromium white cast iron—one of abrasion-resistant white cast iron
There are currently two valuable chromium based Abrasion-Resistant White Cast Iron-resistant white cast iron. One is Ni Hard, another is high chromium white cast iron.
A. Ni- Hard cast iron (nickel hard cast iron)
INCO created Ni – Hard (4.5%Ni, 1.6% ~ 2.0%Cr) martensitic white cast iron in 1932. The United States used it as a liner and an impurity pump overflow parts. Furthermore Japan and Europe countries have the application successively. However, due to the eutectic cementite in the white iron distributes along the A grain boundaries. As a result it seriously affects the mechanical properties of the cast iron (σb20 ~ 25kg/mm2).
In 1963 INCO created an improved Ni – Hard 4 , the content of Cr increased to 9%. And the content of Si is 1.7%, Ni is 6%. The crystal of eutectic carbide changed from the original M3C to M7C3 type [(CrFe) 7C3]. Consequently which greatly improved the mechanical properties (σb 50kg/mm2). Also HV reaches 600~800. It is just less than Cr15- Mo3 high chromium white cast iron. Hence in the production of grinding ring, roller, lining plate of ball mill liner and other castings they have wide application.