43results about How to "Reduce remelting" patented technology

The invention relates to a steel smelting technique, in particular to a converter smelting technique. The invention aims to provide a converter smelting technique, which has the advantages of less splash, and high content of smelting end point carbon and low oxygen content in the mid-high-carbon steel during production process and greatly reduces the remelting caused by excessive carbon content in the low-carbon steel production process. The converter smelting technique comprises the following steps: (1) charging: charging molten iron and scrap steel into the converter; (2) igniting; (3) converting: within 0.5 minutes after starting converting, lowering an oxygen lance to the basic position+200mm; adding lime and lightly fired dolomite within 1.5 minutes; lowering the oxygen lance to the basic position after finishing adding the materials; slowly raising the oxygen lance to the basic position+100 to +200mm and adding lime, lightly fired dolomite, coolant and slag melting agent within 3.5-4.5 times; controlling the oxygen lance to be in the basic position to basic position+600mm within 9.5-12 minutes; and controlling the oxygen lance to be in the basic position-100mm to the basic position after 12 minutes; (4) tapping; and (5) slag splashing repair.

The invention belongs to the technical field of added material manufacturing, and in particular, discloses an added material manufacturing method for synchronous heat treatment. The method comprises the following steps: (S1) powder is paved, and is scanned by laser according to a preset scanning path to finish laser scanning of a present layer; (S2) after spacing by a period of time, the machinedpresent layer is reheated by low-power laser; and (S3) the steps (S1) and (S2) are repeated to finish laser scanning of all layers to obtain needed compact parts. The method reduces the material cooling speed during forming, prolongs the existence time of a molten pool, reduces the formation of cracks and holes, and can be applied to laser added material manufacturing of metal and metal-ceramic composite materials.

The invention belongs to the technical field of soil remediation, and particularly relates to a method for remediation of lead-cadmium polluted soil. A combined remediation method of adsorption solidification and microbial remediation is adopted to remediate lead-cadmium polluted soil. The method particularly comprises the following steps: spreading an adsorbent and a passivator into the soil before crop seeds are sown, spraying water at the same time, then carrying out deep tillage by 5-8 cm, and standing the soil for 10-15 days; and spreading a compound bacterial preparation into the soil, carrying out shallow tillage by 3-5cm, then spraying a film forming solution into the soil, and standing the soil for 10-15 days. Through adoption of the combined remediation method of adsorption solidification and microbial remediation, heavy metals are firstly adsorbed and solidified under action of the adsorbent and the passivator, and then the adsorbed and solidified heavy metals are digested and converted by microorganisms, so that the content of the heavy metals in the soil is reduced, and the heavy metals are prevented from being dissolved again.

The invention relates to a hot rolling plan arrangement method, and belongs to the technical field of metallurgical continuous rolling. The method includes: setting a constraint function, establishing a rolling plan model, solving the rolling plan model, performing programming by employing a computer programming technology, and establishing a continuous casting and rolling production, organization, and management mode. Compared with the prior art, the beneficial effects of the method are that the plan making is flexible, mixed arrangement of different steel kinds, different thicknesses, and different widths can be performed, and crossed rolling is realized; the hot direct rolling rate of hot-rolled slabs is high, the heating time of cold-rolled plates is reduced, and energy is saved; and the function of six-in-one by three machines of the casting billet can be fully achieved, the 215OASP production line realizes tight combination of three processes including steel production, continuous casting, and rolling, and the goal of promoting energy saving and consumption reduction of steel products is achieved.

The invention discloses a method for increasing quality of cathode silver power, aiming to solve the problem that the copper impurity in the cathode silver power exceeds standard. The method comprises the following steps: preparing cathode silver power by controlling the compositions of electrolyte to comprise 90-120g/l of Ag, 8-10g/l of HNO3 and less than 35-60g/l of Cu, and using 20-28g/l of dilute nitric acid to dissolve, soak and rinse the cathode silver power when the copper content in the electrolyte is more than 35g/l, wherein the soaking temperature is 40-50 DEG C, the soaking time is 2h, and the rinsing temperature is 80-90 DEG C. By using the method of the invention, the cost of the 1# cathode silver is reduced and the mass of the product silver ingot is increased. The method has the advantages of low operating intensity, simple equipment, low production cost, capability of not changing the original processing equipment, and the like.

The invention discloses a vermicular graphite cast iron manufacturing process for an automobile engine. The vermicular graphite cast iron manufacturing process comprises the following steps that S1, the content of a graphite interference element in the raw molten iron is firstly taken into consideration, so that the adding amount of the vermicularizing agent is greatly influenced, due to the factthat the vermicular elements in the molten iron are added, a part is consumed in chemical reaction, the process is mainly used for removing oxygen and desulfurization, only the creep elements remaining in the cast iron are effective in changing the shape of the graphite, and if in the molten iron is treated, S, O and graphite are extremely low in interference element content, the amount of the consumed vermicularizing agent is small, the production cost is low, so that when the furnace burden is prepared, a pure material with low sulfur and graphite interference element content should be selected, and the use amount of the material returning is not more than 50%. The alloy is high in alloy utilization rate by adopting a wire feeding method, less in additive consumption, low in treatment cost, low in labor cost, safe and reliable in operation, and small in environmental pollution.

A smonocrystalline silicon include a straight body formed without generating a remelt growth area of 200 μm or more in a height in a growth direction. Growth striations, which are formed radially across the straight body, include a growth striation with an outer end interrupted by another growth striation not to reach a peripheral portion of the straight body. The remelt growth area has the growth striation with the interrupted outer end.

A solder powder (10) of the present invention comprises a core (11) made of silver, a coating layer (12) that coats the core (11) and is made of tin, and a diffusion-preventing layer (13) that is madeof nickel and is between the core and the coating layer. The average grain diameter of the solder powder (10) is 1 [mu]m to 30 [mu]m. The proportional content of silver relative to 100 mass% of the entire amount of the solder powder (10) is 10 mass% to 81 mass%. In a solder powder (10) of the present invention, the thickness of the diffusion-preventing layer (13) made of nickel is proportionally0.04-0.50 if the radius of the core (11) is taken as 1. A method for preparing a solder paste of the present invention is a method in which a solder paste is prepared by mixing a solder powder (10) ofthe present invention with a flux for solder and converting the mixture to a paste.