The microstructure was observed by optical microscope (OM), the microstructure was observed by scanning electron microscope (SEM), the carbide type was analyzed by transmission electron microscope (TEM), the phase composition was detected by X-ray diffraction (XRD), and the chemical composition of carbide and structure was analyzed by electron probe microanalysis (EPMA). The effect of quenching temperature on the microstructure and properties (hardness and impact properties) of high chromium cast iron was studied. On this basis, the effects of natural aging on the microstructure of high chromium cast iron and the effects of structural changes caused by natural aging on the macro hardness and micro hardness of high chromium cast iron were further studied. Combined with the first performance principle, it provides a theoretical explanation for the experimental phenomenon of natural aging.
The main research contents include:
(1) Through destabilization treatment, the effects of different heat treatment temperatures on the matrix structure, secondary carbide size, content, macro hardness and impact properties of high chromium cast iron were studied;
(2) The high chromium cast iron after destabilization treatment was treated by natural aging, and the effects of natural aging on matrix structure, macro hardness and micro hardness were studied. And carry out exploratory experimental research on artificial aging to provide a basis for follow-up research;
(3) Through the first principle, the carbide formation energy of Fe2 xcrxc (x = 1 ~ 2) alloy is calculated to determine its stability; The elastic constants of Fe2 xcrxc (x = 1 ~ 2) alloy carbide are calculated by stress-strain method, so as to calculate its theoretical hardness.