33results about How to "Avoid Coarse Grains" patented technology

The invention provides a molding technology for hub supports. The technology comprises three steps including a blanking step, a forging step and a quenching and tempering treatment step. With the technology, preliminary forging, intermediate forging and final forging are performed in the forging process, coarse grains are prevented through stage-by-stage treatment, and compared with hub supports molded with the prior art, the hub supports have the advantages that the shear strength and the hardness are greatly improved and the comprehensive mechanical performance is improved.

The invention relates to a thermocouple for high-temperature measurement, in particular to a toughened high-temperature iridium-rhodium thermocouple suitable for temperature measurement below 2400K, and belongs to the field of temperature measurement. Including thermocouple wire, insulating porcelain tube, and protective shell; thermocouple wire is placed inside the insulating porcelain tube; the outside of the insulating porcelain tube is covered with a protective shell; between the thermocouple wire and the insulating porcelain tube, and between the insulating porcelain tube and the protective shell The space is filled with high-temperature adhesive for fixing and sealing; it is characterized in that: the positive electrode of the thermocouple is made of IrRh alloy, and the weight percentages of Ir and Rh are respectively 40% to 60% and 60% to 40%; the negative electrode is made of IrRh The weight percentages of alloy, Ir and Rh are 80%-90% and 20%-10% respectively; the positive electrode and the negative electrode are welded into hot junctions; after the hot junctions are welded and the thermocouples are assembled, X needs stress relief annealing. The problem of high brittleness and catalytic effect of traditional iridium-rhodium thermocouples is solved. The breakage of the negative electrode is avoided, and the accuracy of measurement is improved.

The invention relates to a grain control method for production of ultrawide double-zero aluminum foil blanks by electrolytic aluminum liquid cast-rolling process. A smelting furnace holding solid aluminum and electrolytic aluminum liquid in a horizontal aluminum cast-rolling line is used for smelting for 4-10 hours at the low temperature of 720-735 DEG C, the aluminum liquid is heated to 740-750 DEG C in 20-30 minutes, the aluminum liquid is refined after alloy preparation, the aluminum liquid is allowed to stand for 30-50 minutes after refining and is transferred to a standing furnace, the aluminum liquid in the standing furnace is evenly mixed for 10 minutes every 4-6 hours by Ar and CCl4, the aluminum liquid in the standing furnace flows into a filter tank through a degassing tank and a channel and flows to a front tank through the filter tank and the channel, and the aluminum liquid is injected into gaps of casting rollers by a casting spile. With the process coordinating with equipment, adjustable temperature and speed of the aluminum liquid in the casting spile are achieved, and even transverse and longitudinal grain structures of a casting slab can be obtained.

The invention discloses a pipe hot medium internal pressure forming method based on molten glass, and relates to a metal pipe forming method. The problems that according to existing hot medium internal high pressure forming methods, the heating speed is low, heat conducting coefficients are low, sealing is difficult, and forming pressure only can reach about 0-50MPa are solved. The method comprises the steps that 1, a pipe internal high pressure forming temperature interval is determined according to the pipe variety; 2, according to the pipe internal high pressure forming temperature, glass materials are selected; 3, a pipe to be formed is preheated; 4, a pipe blank is vertically placed into a forming die, and die closing and sealing are carried out; 5, the glass materials are heated to obtain molten glass; 6, the glass media are injected into the sealed pipe blank; 7, the pipe blank is heated to internal high pressure forming temperature under high-temperature filling; and 8, material supplementing is carried out; and 9, pressure maintaining is carried out, the molten glass flows out through an overflow valve, die opening is carried out, and the formed deformed-section pipe partis obtained. The pipe hot medium internal pressure forming method is used in the field of internal high pressure forming.

The invention discloses a rolling method of steel for non-quenched and tempered connecting rods of engines and a manufacturing method of forgings. The continuous casting slab is made into material through two fires, one of which adopts high-temperature diffusion heating process, and the total heating time is controlled from 240 to 360 minutes, and the heating time of the high-temperature section is not less than 100 minutes to fully diffuse the segregated elements in the material. The controlled rolling and controlled cooling process is adopted during fire rolling. The forging method includes blanking, induction heating, and controlled cooling. The induction heating temperature is 1200-1230°C, and the cooling rate on the air-cooled line is controlled to be 3-4.5°C / S. Controlling the temperature of the lower air-cooling line of the forging blank at 580-620°C effectively refines the grain size of the connecting rod, improves the strength, toughness and plasticity of the material, prevents abnormal structures, and prevents defects such as surface scratches produce, reduce the proportion of ferrite, and obtain good economic and environmental benefits.

The invention refers to a simple method for small shaft part chromizing, the method includes: (1) the small shaft part and chromizing agent are mixed even and put into the chromizing bottle; (2) seals the bottle and puts the bottle into electrical furnace and seals the furnace door tightly; (3) carries on segmented heating and thermal retardation; (4) chromizing process; (5) cooling; (6) opens the chromizing bottle, pours out the mixer, and takes out the small shaft piece, filters it and eliminates the chromizing agent; (7) hardening and tempering; the special chromizing agent is made up of aluminium oxide, chrome iron powder, ammonium chloride according to the proportion of 55%: 42%: 3%. The device in the invention is simple, low investment; small harm to device. It enhances the wearing resisting and corrosion resisting property of small shaft.

The invention discloses welding seam cooling liquid for use in longitudinal submerged arc welding of steel pipes and a use method thereof. The welding seam cooling liquid for use in longitudinal submerged arc welding of the steel pipes comprises the following specific components in percentage by mass: 5-10 percent of polyvinyl alcohol, 10-15 percent of ethylene glycol, 10-15 percent of propylene glycol, 2-5 percent of glycerol, 1-3 percent of sodium nitrate, 0.5-1 percent of potassium hydroxide, 0.5-1.5 percent of an antifoaming agent, 0.1-1.5 percent of an anticorrosive agent and the balance of deionized water. Through adoption of the welding seam cooling liquid, the cooling speed of a welding seam is increased, and the deformation and cracking of the welding seam are avoided. Meanwhile, the high-temperature retention time of the welding seam is shortened, coarse grains in a weld microstructure are prevented, and the strength and toughness of the welding seam are enhanced.