148results about How to "Low content of impurity elements" patented technology

The invention relates to low nitrogen, low-aluminum ferrotitanium and a manufacture method and an alloy cored wire thereof. The low nitrogen and low-aluminum ferrotitanium is 70Fe-Ti alloy, comprising the impurity elements such as nitrogen, aluminum, silicon, carbon, phosphorus, and sulfur and so on, the content of nitrogen is less than or equal to 0.08 percent and the content of aluminum is less than or equal to 0.5 percent. The content of titanium is 60 percent to 80 percent, the content of silicon is less than or equal to 0.5 percent, the content of carbon is less than or equal to 0.1 percent, the content of phosphorus is less than or equal to 0.04 percent, and the content of sulfur is less than or equal to 0.03 percent, the rest is ferrum. The manufacture method is as follows: in a common smelting method, the industrial salt is used as slagging constituents during the smelting; the sponge titanium, waste titanium, high quality steel scraps or ferroferrite comprising the impurity elements, such as nitrogen, aluminum, silicon, carbon, phosphorus, and sulfur, etc. with low content are used as alloy raw materials, the raw materials are briquetted before smelting; the smelting is carried out in an argon smelting furnace or a consumable electrode vacuum furnace. The low nitrogen and low-aluminum ferrotitanium used as the alloy raw material is applied in manufacturing the high grade steel such as stainless steel, which requires titanium to be used as stabilization alloy element or alloy strengthening element to obtain good combination property in strength, plasticity, ductility, and inoxidability, etc. and which also requires low content of the impurity elements such as nitrogen, aluminum, silicon, carbon, phosphorus, sulfur, etc.

The present invention relates to a method for growth of germanium quantum dots. In the method, germanium quantum dots are grown on graphene interfaces with different quantities of layers. In the present invention, ultra-high uniformity graphene interfaces are introduced on a conventional substrate surface, Ge quantum dots are grown on the interfaces, and complicated cleaning processes for obtaining high-quality interfaces are avoided, and process flows are simplified; in addition, the low-matrix element content and the low defect rate of the germanium quantum dots are ensured, a self-organization growth process of the germanium quantum dots is ensured, and germanium quantum dots with good shape and uniformity are formed.

The invention relates to an electroslag remelting slag system of super duplex stainless steel. The electroslag remelting slag system comprises the following ingredients by weight percentage: 55-74% ofCaF2, 5-20% of CaO, 5-20% of Al2O3, 5-15% of MgO and 1-15% of SiO2. According to the electroslag remelting slag system, optimal slag alkalinity is achieved by adjusting contents of basic oxides, namely CaO and MgO, and acidic oxides, namely SiO2 and Al2O3; and the electroslag remelting slag system is particularly applicable to electroslag remelting of the super duplex stainless steel, improves purity of the super duplex stainless steel, reduces a content of harmful impurity elements, optimizes an ingot structure, greatly improves processability of the stainless steel increases a hot processing yield and contributes to achieving excellent mechanical properties and corrosion resistance.

The invention discloses a method for preparing a high-speed steel composite roll for hot rolling. The method is characterized by comprising the following steps of: firstly, manufacturing a regenerated high-speed steel composite roll collar by adopting an electroslag hollow stripping method; melting low-cost nodular cast iron or plain carbon steel by utilizing an intermediate frequency furnace or an electric arc furnace; manufacturing a roll core by a casting method; and fusing the roll outer collar and the roll core together in the manner of casting to prepare the composite roll for the hot rolling, wherein the working roll collar of the composite roll for the hot rolling is made of high-speed steel, and the roll core is made of the nodular cast iron or the plain carbon steel. The high-speed steel composite roll prepared by the method disclosed by the invention has the characteristics that the outer layer thickness is even, the tissue is fine and compact, and the nodular cast iron or the plain carbon steel is adopted to serve as the material of the roll core. The quality of the working face of the roll is comprehensively improved by utilizing the dual action of rare earth treatment and electroslag refining during a process of manufacturing the roll collar, and the service life is long. A roll body and the roll core are respectively made of the nodular cast iron or plain carbon steel, so that the integrated cost is low. The method disclosed by the invention is suitable for manufacturing the high-speed steel composite roll for the hot rolling and can be widely applied in metallurgical industry and renewable resource industry.

The invention discloses a method for manufacturing a molybdenum plate blank through sintering. The method includes the steps that firstly, raw materials are weighed, and the weighed raw materials are evenly mixed, and mixed molybdenum powder is obtained; secondly, the mixed molybdenum powder is pressed into a plate blank in a cold isostatic pressing manner; and thirdly, under the hydrogen atmosphere, the plate blank is heated and sintered, and the molybdenum plate blank is obtained after being naturally cooled. Heating and sintering include the specific steps that firstly, the plate blank is firstly heated to 900 DEG C and sintered for 1 hour to 2 hours at the temperature of 900 DEG C, then the plate blank is heated to 1,500 DEG C and sintered for 2 hours to 4 hours at the temperature of 1,500 DEG C, and then the plate blank is heated to 750 DEG C to 1,780 DEG C and sintered for 6 hours to 10 hours at the temperature of 750 DEG C to 1,780 DEG C. According to the method, molybdenum powder used in the method is common brands of molybdenum powder in the market, cost is controllable, and purchase is easy; the apparent density of the mixed molybdenum powder is increased, fluidity is improved, a rubber sleeve is filled with the molybdenum powder more easily in the powder filling process, and the plate profile of the pressed blank is improved; and the maximum sintering temperature is lowered, and the loss of equipment and the like and energy consumption are reduced.

The invention relates to a spherical titanium and titanium alloy powder preparation device and method. The device comprises a smelting chamber (12), an atomizing chamber (11), a rotating wheel (3), a smelting unit (4), a lifting device (5) and a primary powder collecting tank (7), the rotating wheel (3) is rotationally arranged in the smelting chamber (12) and located above the smelting unit (4), the smelting unit (4) moves through the lifting device (5), the smelting chamber (12) is communicated with the atomizing chamber (11), a communication port is located on the tangent line of the rotating wheel (3), and the primary powder collecting tank (7) is communicated with the atomizing chamber (11). The method comprises the following steps: a, alloy ingot smelting; b, atomizing molten drops; c, collecting powder; and d, screening the powder. And a rotating wheel is adopted to throw out the melt for heat exchange to prepare the spherical titanium or titanium alloy powder which is fine in granularity, low in hollow rate, high in sphericity degree and low in oxygen content. The problems that according to an existing spherical titanium and titanium alloy preparation method, the oxygen content, the hollow rate and the impurity content of powder are high are solved.

The present invention relates to the production method of niobium powder and / or tantalum powder; The method is carried out by reducing oxygen-containing alkali metal fluoroniobate and / or oxygen-containing fluorotantalate, wherein the reduction reaction temperature is 300-1050 °C, using at least one alkali metal plus at least one halide selected from Mg, Ca, Sr, Ba, Ce and the oxygen-containing alkali metal fluoroniobate and / or oxygen-containing fluorotantalate Reaction takes place to produce niobium powder and / or tantalum powder; the reduction recovery rate is high during niobium powder and tantalum powder produced according to the inventive method, and the produced niobium powder and tantalum powder have large specific surface area, large porosity, and higher oxygen content Low, when used to make capacitor anodes, it has the characteristics of large open porosity, low leakage current and high specific volume; the invention is convenient for industrial production.