1 results about "Graphite morphology" patented technology

This invention discloses a gradient-strengthened dual high-carbon phase MoCr alloy cast iron and its preparation process, belonging to the technical field of alloy cast iron materials. This alloy cast iron contains 3.0-3.2% C and 1.7-1.9% Si by mass percentage, with a carbon equivalent of 3.7-3.9%. It forms a gradient structure from the surface to the core, consisting of a carbide-rich layer, a transition strengthening layer, and a matrix layer. The carbide content, graphite morphology, and grade of each layer are gradient-adapted, and the mechanical properties meet the requirements of tensile strength ≥390MPa and quenching hardness 56-59HRC. The preparation process includes raw material pretreatment and precise batching, segmented melting and gradient inoculation, directional solidification and gradient cooling, gradient heat treatment and performance regulation, and can also include surface strengthening and defect repair steps. This invention achieves a synergistic improvement in material strength, toughness, wear resistance, and fatigue resistance, completely eliminates the problem of quenching pitting, is compatible with existing production lines, has low raw material costs, and a high casting yield rate, making it suitable for the manufacture of cold stamping and drawing dies for automotive body panels.