69results about How to "The smelting process is stable" patented technology

The present invention relates to austenitic stainless steel welding wire for gas protected welding in vehicle. The austenitic stainless steel welding wire has the chemical composition comprising C not more than 0.03 wt%, Si 0.50-0.90 wt%, Mn 1.00-2.50 wt%, P not more than 0.025 wt%, S not more than 0.015 wt%, Ni 9.0-14.0 wt%, Cr 19.5-24.5 wt%, and Fe and inevitable impurity for the rest. The austenitic stainless steel welding wire produced through smelting, rolling, drawing and other steps has excellent performance, including excellent welding performance, is applied for welding steel of 500-700 MPa strength to form weld seam with high strength, high toughness and high corrosion resistance.

The invention relates to a high-strength and high-toughness automatic submerged arc welding wire with weathering resistance and mainly aims at overcoming disadvantages of poor atmospheric corrosion resistance, high production cost and the like of the existing submerged arc welding materials. In term of technical measures, the welding wire is made from the following chemical components by weight percent: C: 0.05-0.12, Si: 0.01-0.10, Mn: 1.50-2.1. S: not more than 0.015, P: not more than 0.020, Ni: 0.20-0.60, Cr: 0.20-0.50, Cu: 0.25-0.50, Ti: 0.05-0.16, B: 0.002-0.010, Als: 0.001-0.015, Fe and other unavoidable impurities. The welding wire is matched with a basic sintered flux for welding, a weld joint has excellent atmospheric corrosion resistance and comprehensive mechanical properties, and a deposited metal at a weld seam has tensile strength up to 560MPa and ballistic work up to 107J at -40 DEG C and up to 87J at -50 DEG C.

The invention discloses a method for precisely controlling the nitrogen content in nitrogen-containing steel smelting in a vacuum induction furnace. The method comprises the following steps that an iron and steel stock of which the surface is clean is placed into a crucible of the vacuum induction furnace, and power is supplied for heating when the vacuum induction furnace is vacuumized to be below 10 Pa; after the iron and steel stock is molten down completely, the temperature is raised to 1550-1650 DEG C, and then heat preservation is performed; vacuumizing is stopped, and then argon is introduced in for alloying; after contents of other alloy elements except nitrogen reach target values, and the vacuum degree is smaller than or equal to 100Pa, nitrogen is introduced into the furnace; after the pressure of nitrogen in the furnace reaches a preset value, inflation is stopped, and nitrogen alloying is performed in a nitrogen atmosphere in the furnace by maintaining a certain gas nitriding time period; after nitrogen alloying is finished, the temperature of molten steel is adjusted; and nitrogen is introduced in the furnace again, and after the pressure in the furnace is increased to 10000-20000 Pa, pouring is performed, so that an ingot casting which is precise in content and compact and uniform in inner part is obtained. The method is applicable to smelting of steel types of which the nitrogen content is 0.005%-0.05%; by utilizing the method, the nitrogen content in steel can be precisely controlled in a range of a target value +/-5PPm; and the molten steel is high in cleanness, and the ingot casting is compact and uniform.

The invention discloses a producing technics of squama graphite carbon electrode, its material use following powder gravity percentage: 0.075-0.15mm petroleum coke powder after calcining 23-28%, 0.075-0.15mm squama graphite powder 2-8%, 0.5-4mm petroleum coke after calcining 18-23%, 4-10mm petroleum coke after calcining 11-19%, 4-10mm electric calcining anthracite 6-14%, 10-16mm petroleum coke after calcining 2-10%, warm pitch of binder 16-20%, pugging, forming, baking the above material, then machining, the carbon electrode smelt industry silicon which is produced by the invention, the yield can be improved greatly, the consuming of electrode and electric energy can be reduced, so does the producing cost.

The invention discloses an intermediate alloy for preparation of titanium alloy and a preparation method thereof, relating to aluminum-molybdenum-tin (aluminum-molybdenum-tin-based) intermediate alloys for preparation of the titanium alloy and preparation methods thereof. The alloy is characterized by containing the following alloy compositions in percentage by weight: 20.0-25.0% of Mo, 20.0-25.0% of Cr, 10-15% of Sn, 10-15% of Zr and the balance of Al. According to the aluminum-molybdenum-tin-chromium-zirconium alloy disclosed by the invention, metallic compounds, which take molybdenum, tin, chromium, zirconium and the like as main ingredients, have the characteristics of good brittleness and easiness in fracture, and a titanium alloy production process is shortened and is easier in operation. According to the preparation method, oxides are taken as raw materials, so that the cost is low, the smelting process is stable, and the state of alloy forming is good; the alloying is uniform, and elemental metals are added to titanium sponge and aluminum beans in the form of intermediate alloy, so that the degree of segregation of the titanium alloy is lowered.

The invention discloses a converter steelmaking method for molten iron [Si] (0.50%). The converter steelmaking method comprises the following steps: confirming objective temperature, objective carbon,final phosphor, dephosphorizing rate and alkalinity of final residue according to different types of steel; calculating lime addition amount, dolomite addition amount, sinter addition amount and oxygen addition amount during a blowing process according to oxygen balance and heat balance; performing circular smelting in the smelting sequence of leaving residue in the converter, protecting the converter by splashing residue, adding waste steel and mixing with iron, blowing and then tapping. According to the invention, the slag amount and the process splashing phenomenon can be reduced and the consumption of lime and dolomite can be reduced without influence on the dephosphorizing rate.

The invention discloses an electric furnace steel-making method utilizing like graphite to replace pig iron to match with carbon. The like graphite with a certain shape is used for partly or entirely replacing raw steel, and the like graphite is added by a material basket or directly added into the furnace by an overhead bunker to perform steel-making production. The invention can reduce the cost of the electric furnace steel making, and is suitable for an electric furnace steel making process.

The invention provides an Al-V-Cr-Fe-Ti intermediate alloy and a preparation method thereof, relating to an Al-V (Al-V-based) intermediate alloy for preparing titanium alloy and a preparation method of the Al-V (Al-V-based) intermediate alloy. The Al-V-Cr-Fe-Ti intermediate alloy is characterized by being prepared from the following components in percentage by weight: 26.0-32.0% of V, 20.0-25.0% of Cr, 6-10% of Fe, 6-10% of Ti and the balance of Al. A metallothermic reduction method is adopted in the preparation process. The Al-V-Cr-Fe-Ti intermediate alloy as a metallic compound with vanadium, chromium, titanium, ferrum and the like as main components has the characteristics of good brittleness and breakability and can be used for shortening the production process of titanium alloy and ensuring that the production process of the titanium alloy is easier to operate. Oxides are used as raw materials, so that the Al-V-Cr-Fe-Ti intermediate alloy is low in cost, stable in smelting process and good in alloy formation state; in addition, the Al-V-Cr-Fe-Ti intermediate alloy is uniform in alloying and is added into titanium sponge and aluminum shots in an intermediate alloy form, so that the segregation degree of the titanium alloy is reduced.

The invention discloses a method for smelting ultra-low carbon steel with carbon lower than or equal to 20 PPm. The method comprises the steps that molten iron desulphurization is conducted through pure magnesium and slaked lime, smelting in another furnace is conducted, high carbon ferromanganese is added according to high oxygen content; argon blowing is conducted; vacuum treatment is carried out inside a RH furnace; vacuum decarburization is conducted, a low-carbon refining agent is added to carry out desulfuration and slugging, and when the vacuum treatment is conducted for 15 min, aluminum balls are added; after recycling is conducted for 3 min, silicon iron, ferromanganese, a low-carbon desulfurizing agent are added immediately, and after the recycling is conducted for 5 min, the vacuum treatment is finished; the aluminum balls are sprinkled on the surface of steel slag, and after the total content of iron oxide and MnO in the slag is lower than 5.5 wt%, a later procedure is conducted. On the premise that the mechanical property of the ultra-low carbon steel is guaranteed, the carbon can be lower than or equal to 20 PPm, parts of low-carbon ferromanganese is replaced with parts of the high carbon ferromanganese, the carbon content is lower than 0.15 wt%, parts of slugging materials and parts of a deoxidizing agent are replaced with the low-carbon refining agent and the low-carbon desulfurizing agent, the cost can be lowered by at least 30 yuan per ton of steel, the smelting process is stable, and slagging is good in the refining process.

The invention provides a high-strength high-toughness weather-resistant gas protection welding wire for steel. The welding wire steel comprises, in weight percentage, 0.03%-0.11% of C, 0.70%-1.50% of Mn, 0.25%-0.90% of Si, 0.55%-1.40% of Ni, 0.15%-0.45% of Cu, 0.05%-0.18% of Ti, not more than 0.015% of S, and not more than 0.020% of P, the balance being iron and inevitable impurities. The welding wire is used for the welding of steel of the 550 MPa strength grade; the welding wire steel smelting process is stable and easy to implement, and the technical requirements for welding high-strength, high-toughness and high-weather resistance steel are met. The gas protection welding wire has excellent welding process properties, has the advantages of stable welding arcs, less splatter, zero gas pores and artistic formation and is suitable for all-position welding.

The invention relates to an aluminum-tantalum-molybdenum intermediate alloy and a preparing method thereof, in particular to an intermediate alloy for titanium alloy production and a preparing method thereof. The intermediate alloy is characterized by comprising, by weight, 27.0% to 32.0% of Ta, 18.0% to 23.0% of Mo, and the balance of Al; metallothermic reduction is adopted in preparation. The intermediate alloy is a metallic compound comprising mainly tantalum, molybdenum and aluminum and features crispiness and breakage proneness; the production process of the titanium alloys is shortened; the production of the titanium alloys is easier to operate. By the use of oxides as raw material, the cost is low, the smelting process is stable, and the alloy is in good formation state; alloying is uniform; by adding the intermediate alloy into titanium sponge and aluminum shots, segregation degree of the titanium alloys is lowered.

The invention relates to an intermediate alloy for producing titanium alloy and a production method thereof, in particular to an Al-Nb-Si-Ti intermediate alloy and a preparation method thereof. The Al-Nb-Si-Ti intermediate alloy is characterized by comprising, by weight, 22.0% to 28.0% of niobium, 4.0% to 6.0% of silicon, 18.0% to 22.0% of titanium and the balance of aluminum. The preparation method is characterized in that metal thermo-reduction is used during the preparation process. The Al-Nb-Si-Ti intermediate alloy, a metallic compound mainly composed of niobium, silicon, titanium and aluminum, has the advantages that the brittleness is good, the breaking is easy, the production process of the titanium alloy is shortened, and the production process of the titanium alloy is easier to operate; oxide serves as raw material, the cost is low, the smelting process is stable and the forming state of the alloy is good; the alloy in the intermediate alloy form is added into sponge titanium and aluminum shot, and the segregation degree of the titanium alloy is reduced.

The invention provides a sintering method for silicon manganese alloy dust. According to the method, high temperature resistant coke powder used as a sintering adhesive of manganese mineral powder and dust and a plant fiber serving as combustion improver are sintered at the temperature of 800-1,200 DEG C to obtain massive porous sintered products. The finished product has high mechanical strength, the situations of dusting in the sintering process and massive dust generation in the melting process can be avoided. The sintering method is a good method for treating dust and fine mineral powder in manganese plants, and is low in production cost and high in treatment quality.

The invention provides a molten steel deoxidizing and microalloying method. The molten steel deoxidizing and microalloying method comprises the following steps of blowing oxygen to the top of a top-bottom combined blowing converter, blowing inert gas to the bottom of the top-bottom combined blowing converter for smelting, or blowing inert gas to the bottom of molten steel in an electric furnace for smelting; after main chemical components are qualified, blowing a deoxidizing agent to the bottom with inert gas as a carrier for refining; and when the oxygen content in the molten steel is less than or equal to 200 ppm, blowing alloyed powder into the molten steel with inert gas as a carrier for microalloying treatment, wherein the blowing amount of the alloyed powder is less than or equal to10 kg/t of the molten steel.According to the molten steel deoxidizing and microalloying method, the inert gas is blown to the bottom, and after the deoxidizing agent is blown into the molten steel todeoxidize the molten steel, the alloyed powder is blown for direct microalloying, so that components of the molten steel can be more uniform; a brand new concept is provided for directly microalloyingmicroalloy elements in the steel material production process; the microalloy elements existing in the form of solid solution can be effectively obtained out of a steel material, and thus, the steel performance is improved.

The invention discloses a method for producing calcium ferrite from iron oxide. The method utilizes an iron electrode to realize electric smelting, utilizes the iron electrode to produce calcium ferrite, prevents an additional component from entering into calcium ferrite, improves calcium ferrite purity and realizes better calcium ferrite actual use effects. In steel-making, through use of the calcium ferrite obtained by the method, a slagging rate is fast, dephosphorization efficiency is high, a lime use amount is reduced, fluorine-free steel-making is realized and environmental pollution is reduced.

The invention discloses a vacuum medium-frequency induction furnace smelting method for high-purity low-carbon steel. Pure iron is adopted as a smelting raw material, shot blasting treatment is carried out on the pure iron to remove oxidized scales on the surface of the pure iron and improve the purity of the smelting raw material; vacuumizing is started before the raw material is heated, the rawmaterial is in a vacuumizing state all the time before being heated and melted, and the gas content of the smelting raw material and the gas content of the furnace body environment are reduced; and after the raw material begins to melt, vacuumizing is stopped, and argon is introduced to serve as protective gas till smelting and pouring are finished. According to the vacuum medium-frequency induction furnace smelting method for the high-purity low-carbon steel, the problem that molten steel is oxidized insufficiently due to non-vacuum smelting of a low-carbon steel medium-frequency induction furnace is solved.