36results about How to "Prevent gestational decline" patented technology

The invention relates to a trace alloying process of ductile iron. The trace alloying process of the ductile iron comprises the following steps of a step of spheroidizing, primary inoculation treatment and feed wire method trace alloying and a step of secondary inoculation treatment and poured-over method trace alloying. With adoption of the trace alloying process of the ductile iron, the strength and the plasticity of the produced ductile iron are obviously improved, the tensile strength is larger than 750MPa, the yield strength is about 560MPa, and the percentage elongation after fracture is above 7.5 percent.

The invention discloses an inoculation treatment method of cast iron, which comprises the following steps: directly pouring molten iron without inoculation treatment into a pouring furnace; The second inoculant is added to the water outlet end through the flow inoculation device to carry out the second inoculation treatment. By adopting the inoculation treatment method of the present invention, the inoculation effect of molten iron is good and the production cost is low.

The invention discloses pipe die powder for centrifugally casting a nodular cast iron pipe and a preparation process thereof. The pipe die powder comprises the following components in percent by mass: 60-65 percent of Si, 1.5-2.0 percent of Ca, 2.0-3.0 percent of Ba, 1.4-1.6 percent of Mn, 1.0-1.5 percent of Mg, 1.0-2.0 percent of Zr, 0.7-1.5 percent of Al and the balance of Fe; and the granularities of pipe die powder comprise less than 1.5 percent of 80 mu, 25-30 percent of 100-120 mu, 40-50 percent of 140-180 mu, 25-30 percent of 200-300 mu and less than 2.5 percent of more than 300 mu. The preparation process comprises the following steps of: preparing, melting, pouring, cooling, crushing, milling, proportioning granularities and packaging in vacuum. The pipe die powder has the advantages of uniform components, consistent melting points and reasonable granulometric class, and is beneficial to the prolonging of the service life of a pipe die of the nodular cast iron pipe, the reduction of a series of casting defects of cockles, poor nodulizing, surface cracks and the like of the nodular cast iron pipe, the improvement of the quality of the nodular cast iron pipe and the yield, and the lowering of the production cost.

The invention discloses a die cavity structure of a back box body casing of a wind power generating unit and a method. The structure comprises a casting system, a back box body die cavity and an air outlet opening, wherein the air outlet opening is formed in the back box body die cavity; the casting system comprises a sprue and a cross pouring gate communicating with the sprue; the cross pouring gate sequentially communicates with a first transition pouring gate, a second transition pouring gate, a third transition pouring gate and a fourth transition pouring gate; the fourth transition pouring gate communicates with the back box body die cavity through a flow gate; a first buffer pouring gate is arranged on the cross pouring gate; the ratio of the cross section area of the first buffer pouring gate to the cross section area of the sprue is 1:(0.60 to0.75). The die cavity structure has the advantages that the iron liquid mold filling instability and turbulence generated by the metal liquid in the casting process can be reduced; the quality stability of the casting can be improved; the slag inclusion defects and air hole defects are reduced; the high-quality requirements can be met.

The invention discloses an oxidation-resistant alloying grey cast iron and a preparation method of the oxidation-resistant alloying grey cast iron. The cast iron comprises the following components by mass percentage: 3.0-3.2% of C, 1.8-2.0% of Si, 0.50-0.70% of Mn, 0.10-0.50% of Cr, 0.20-0.30% of Ni, 0.03-0.50% of Mo, 0.5-3.0% of Al, 0.05-0.08% of Sr, 0.005-0.15% of Zn, and the balance of Fe and inevitable impurities. The preparation method comprises the steps of melting raw materials, culturing and processing, and pouring, wherein the tapping is carried out at 1450 to 1550 DEG C after melting; the molten iron is processed by being flushed in a ladle and cultured and processed along with the flow, and then slagged and casted. According to the oxidation-resistant alloying grey cast iron provided by the invention, the organization of the grey alloying cast iron material is structured by distributing 6-8 grades of D type graphite with little graphite of A type on a ferrite substrate, so that higher toughness, high heat conductivity and high-temperature oxidization resistance can be achieved, and good casting technical performance can be ensured as well; and the oxidation-resistant alloying grey cast iron can be applied to manufacturing a glass die and a light alloy metal type casting die which can bear the heat impacting of high-temperature formed liquid and cold-heat alternating stress for a long time.

The invention discloses a preparing method of a nucleating agent for a cam shaft. The preparing method comprises the following steps that 60-75% of Si, 0.01-1.0% of Al, 0.05-0.5% of Ca, 0.1-1.0% of Ba, 3-5% of Cr, 0.03-0.05% of V, 5-8% of Nd, 0-1% of Mn, 0.5-1% of carburant and the balance Fe which are evenly mixed are melted, stirred, poured, cooled rapidly and crushed and then are mixed with Fe3O4 powder to be pressed into pellets to be crushed. The invention further discloses specific application of the nucleating agent for the cam shaft. By means of the nucleating agent for the cam shaft, the comprehensive performance of the cam shaft can be improved, and the nucleating efficiency is improved.

The invention relates to a synthesis and preparation process for a high-silicon-molybdenum ductile iron material. The synthesis and preparation process specially comprises the following steps that raw materials are prepared, and the raw materials comprise, by mass, 60%-70% of scrap steel, 25%-35% of cast iron, 1%-1.2% of silicon iron, 1%-1.3% of ferro-molybdenum and 2%-2.5% of carburant; in the raw material melting process, furnace burdens are added in three batches; all the cast iron and 1 / 3 mass part of scrap steel are added in the first batch of furnace burdens, 5 / 11 mass part of carburant and 1 / 3 mass part of scrap steel are added in the second batch of furnace burdens, and 5 / 11 mass part of carburant and 1 / 3 mass part of scrap steel are added in the third batch of furnace burdens; after the third batch of furnace burdens are completely molten down, all the silicon iron and ferro-molybdenum are added, and when the temperature of molten iron rises to 1400-1410 DEG C, the remaining 1 / 11 mass part of carburant is added in a mirror surface mode after slagging-off impurity removal; and sampling analysis, blending, tapping, nodulizing and inoculation treatment are performed until pouring is completed. According to the process, the scrap steel is used as a main raw material, and the joint carbon adding mode of middle adding and mirror surface adding is adopted for preparing high-silicon-molybdenum ductile cast iron with high strength and high impact toughness.

The invention discloses a preparation method for controlling the eutectic degree of molten iron to optimize the shrinkage cavity of castings, comprising the following steps: S1. Measuring the eutectic degree of the original molten iron: measuring the solidification temperature curve of the molten iron in a sample cup by using a thermal analysis method , Observing the phase diagram, according to the principle of phase transition, it is known that the liquidus temperature is consistent with the solidus temperature, then the intersection point of the composition and temperature is the eutectic point, and the carbon equivalent, silicon equivalent and phosphorus content of the eutectic point are measured by instruments. The invention also proposes a system for controlling the eutectic degree of molten iron to optimize the shrinkage cavity of castings. The system adopts a cupola furnace for furnace material smelting, and uses an H27880 molten iron quality management instrument to detect components of molten iron. The present invention uses high-precision thermal analysis and temperature detection means to continuously optimize the control targets of eutectic degree, maturity, and superheat of molten iron, starting from preventing inoculation recession, eliminating proanatoid graphite structure, and optimizing the solidification structure of molten iron step by step , reduce shrinkage porosity, improve mechanical properties, reduce energy consumption, and maximize benefits.