4results about How to "Coarse grain" patented technology

The invention discloses a gradient ultra-low resistivity electrode steel and a manufacturing method thereof. The mass percentage of chemical components is as follows: C: 0.001-0.003%, Si: 0.0005-0.001%, Mn: 0.008-0.01%, P≤0.006%, S≤0.002%, O: 0.002-0.003%, Cu: 4.3-5.2%, and the rest is Fe and impurity elements. The manufacturing method comprises the steps of molten iron desulfurization, converter smelting, LF furnace refining, RH vacuum treatment, continuous casting, heating, rolling and cooling. The low resistivity of the electrode steel is further reduced by component design, and the resistivity of the electrode steel is made into a gradient distribution by a preparation process, the central resistivity is low, the surface resistivity is high, the current passes through the central part of the flat steel, and the power consumption in the aluminum electrolysis process is reduced.

The application discloses a kind of based on liquid tungsten oxide carbon thermal reduction ultra-coarse tungsten carbide powder preparation method, belong to powder metallurgy technical field.The method includes: tungsten oxide is mixed with carbon black, and mixed powder is obtained;The mixed powder is placed in inert atmosphere and is treated by three-stage heating, so that the tungsten oxide is dehydrated, pre-reduction is experienced, and is melted into liquid state, and carbon thermal reduction reaction is carried out with the carbon black;After reaction, in-situ weak oxygen decarburization treatment is carried out, and the ultra-coarse tungsten carbide powder is obtained;The three-stage heating is: first stage is heated to 280-320 DEG C and is dehydrated, second stage is heated to 1150-1200 DEG C and is pre-reduced, and third stage is heated to 1250-1600 DEG C, so that tungsten oxide is in liquid melt state, and carbon thermal reduction reaction occurs with carbon black.The method provided by the application has the advantages of simple process, wide raw material adaptability, high product purity, uniform grain and the like.

This invention relates to the field of magnesium alloy smelting technology, and in particular to a smelting process and apparatus for a semi-solid non-dendritic slurry of rare earth AS-based magnesium alloy. Using AS magnesium alloy as the base material and a Ce-La-Nd ternary rare earth mixture as the rare earth modifier, the process involves vacuum melting, electromagnetic stirring, and stepped cooling to obtain an ingot. A three-dimensional curve is plotted based on the JMAK equation to determine the critical temperature. Using a rheological casting apparatus, through internal cooling gradient, stirring-assisted slurry preparation, and ultrasonic-assisted isothermal treatment, combined with three-level quality judgment and defect closed-loop adjustment, a slurry with controllable liquid phase content, fine and rounded grains, and uniform rare earth distribution is prepared. The process exhibits high repeatability and meets the requirements of high-end semi-solid forming.

The present invention belongs to the field of refractory materials technology in the field of new materials for smelting or refining furnace linings of special steels such as clean steel, special steel, stainless steel, etc., and specifically relates to a hydration-resistant, corrosion-resistant low-carbon unburned magnesium calcium carbon brick and a manufacturing method thereof. The present invention can improve the hydration resistance of magnesium calcium carbon unburned bricks during mixing, pressing, heating and curing, storage, and transportation, and improve the corrosion resistance of magnesium calcium carbon products, thereby increasing the service life of the smelting furnace, reducing energy consumption, and achieving green production.