6 results about "Graphite morphology" patented technology

The present application relates to a kind of graphite morphology and spheroidization rate analysis system and method based on image processing, belong to the technical field of graphite morphology analysis. Including the following steps: S1, obtaining the two-dimensional metallographic image of the measured nodular cast iron;S2, the two-dimensional metallographic image is handled, to separate each graphite particle in image;S3, extract and calculate the multiple shape factor of each graphite particle, the shape factor at least includes roundness, convexity and sharpness;S4, based on the preset determination threshold, whether each graphite particle is qualified spherical graphite is comprehensively judged;S5, based on the area of qualified spherical graphite, the spheroidization rate of the measured nodular cast iron is calculated;S6, output analysis report containing the spheroidization rate. By the present application, the technical problem that single roundness is prone to misjudgment high-risk graphite in the prior art spheroidization rate analysis method is solved.

The invention discloses high-hardness and high-toughness MoCr alloy cast iron for an automobile drawing die and a preparation process thereof.The alloy cast iron comprises, by mass, 3.1%-3.3% of C, 1.6%-1.8% of Si, 0.7%-0.9% of Mn, 0.8%-1.0% of Cr, 0.3%-0.4% of Mo, 0.2%-0.3% of Cu, 0.1%-0.2% of V, 0.05%-0.1% of Nb and the like, the carbon equivalent is controlled to be 3.6%-3.8%, the graphite form is A + B type, and a nanoscale VC + NbC composite dispersion strengthening phase and an epsilon-Cu precipitation phase are dispersed in a matrix; the preparation technology comprises the steps of raw material pretreatment and precise burdening, electric arc furnace smelting and vacuum refining, compound inoculation and A + B type graphite induction, lost foam casting and gradient cooling, double-stage heat treatment and the like, and optional defect repairing. According to the alloy cast iron and the preparation method thereof, through multi-element synergistic strengthening and precise process regulation and control, the tensile strength of the alloy cast iron is larger than or equal to 380 MPa, the impact toughness ak is larger than or equal to 22 J / cm < 2 >, the quenching hardness is 55-58 HRC, the alloy cast iron has high hardness and high toughness, the problem that a traditional material is strong and brittle is solved, the high-frequency stamping requirement of an automobile drawing die is met, the performance is stable, and the industrial adaptability is high.

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.

The utility model is applicable to the technical field of casting, and provides an automatic weighing and adding device for inoculants, which comprises a mounting frame, and a feeding bin, a mixing bin and a storage bin which are mounted on the mounting frame, the feeding bin, the mixing bin and the storage bin are sequentially communicated, a mixing cavity formed by a structural plate is arranged in the mixing bin, and the structural plate is arranged in the mixing cavity. A mixing cavity is formed in the mixing bin, a discharging cavity is formed in the bottom of the mixing cavity, a mixing assembly is arranged in the mixing cavity, a discharging assembly is arranged at the bottom of the mixing cavity, and the mixing assembly comprises a mixing shaft rotationally installed on the mixing bin and a stirring rod arranged on the mixing shaft in a sleeving mode. The device solves the problems of casting mechanical property difference and abnormal graphite form caused by insufficient mixing of the inoculants, and achieves the effects that different types of inoculants are automatically weighed, fully and uniformly mixed and then added into casting equipment, and the influence on the casting performance due to insufficient mixing of the inoculants is avoided.

The invention discloses a low-stress iron alloy casting forming process for a high-strength driving unit shell, relates to the technical field of machine manufacturing, and aims to solve the technical problem that the high-strength state and the low-stress state of the current driving unit shell cannot be balanced after casting. Adding foundry returns into the output raw materials, outputting the foundry returns to an electric furnace for smelting, detecting alloy element states in molten iron, adding stream inoculants and instantaneous inoculants according to the alloy element states, preheating a casting mold, and demolding after cooling is completed, so that casting is completed. According to the method, molten iron added with the composite alloy additive is stirred at a constant speed in the third step, it is guaranteed that alloy elements are evenly distributed in the molten iron, local stress concentration caused by coarse grains can be effectively relieved, meanwhile, the spheroidized graphite form after casting can reduce the cutting effect on a matrix, stress concentration generated at the tip end of graphite is avoided, and the service life of the graphite is prolonged. The casting internal stress is further reduced.

The invention relates to a graphite form and spheroidization rate analysis system and method based on image processing, and belongs to the technical field of graphite form analysis. Comprising the following steps: S1, obtaining a two-dimensional metallographic image of nodular cast iron to be detected; s2, processing the two-dimensional metallographic image so as to segment each graphite particle in the image; s3, extracting and calculating a plurality of shape factors of each graphite particle, wherein the shape factors at least comprise roundness, convexity and sharpness; s4, comprehensively judging whether each graphite particle is qualified spherical graphite or not based on a preset judgment threshold value; s5, calculating the spheroidization rate of the to-be-measured nodular cast iron based on the area of the qualified spherical graphite; and S6, outputting an analysis report containing the spheroidization rate. According to the method, the technical problem that high-risk graphite is easily misjudged due to the fact that an existing spheroidization rate analysis method depends on single roundness is solved.