34results about How to "Improve nitriding effect" patented technology

The invention discloses a nanometer material contained ladle bottom argon blowing permeable brick and a preparation process thereof. The permeable brick comprises components of high-purity corundum, spinel, alpha-Al2O3 micro powders, nano calcium carbonate, Si powders, binding agents and antiknock agents. The preparation process of the nanometer material contained ladle bottom argon blowing permeable brick includes the following steps of dosing, fine powder premixing, stirring, vibration forming, curing with molds, demolding, drying and baking. According to the nanometer material contained ladle bottom argon blowing permeable brick and the preparation process thereof, Cr2O3 is not used, and during usage, new pollutants are not generated, so that pollution treatment costs are reduced, and high environmental benefits are achieved; micropores are evenly distributed in the brick, so that cracks are effectively prevented from continuing spreading during usage, the toughness of the permeable brick is improved, the spalling is reduced, the service life of the permeable brick is prolonged, the permeable brick is basically free from bonding slag after usage, cleaning during usage is reduced, and production costs of iron and steel enterprises are reduced.

A steel piston ring and a steel cylinder liner are described which comprise as the main body a steel composition which has good nitridability. The steel composition consists of the following elements: 0-0.5 weight % B, 0.5-1.2 weight % C, 4.0-20.0 weight % Cr, 0-2.0 weight % Cu, 45.30-91.25 weight % Fe, 0.1-3.0 weight % Mn, 0.1-3.0 weight % Mo, 0-0.05 weight % Nb, 2.0-12.0 weight % Ni, 0-0.1 weight % P, 0-0.05 weight % Pb, 0-0.05 weight % S, 2.0-10.0 weight % Si, 0-0.05 weight % Sn, 0.05-2.0 weight % V, 0-0.2 weight % Ti and 0-0.5 weight % W. The steel piston ring and the steel cylinder liner can be manufactured in a casting process using the machinery and technology employed for the manufacture of cast iron parts.

A method of producing a workpiece of a heat-resistant steel, such as hot forming tool steel, where the workpiece may be hardened and depassivated after mechanical machining and electrochemical treatment. The hardening including a reduction step, so that no depassivation need be performed by pickling, for example, before nitriding. The result of the hardening treatment is a favorable surface condition for stepwise nitriding.

The invention discloses a medium and low-carbon alloy constructional steel surface pressurization gas-nitridation method. The medium and low-carbon alloy constructional steel surface pressurization gas-nitridation method comprises the following steps of putting a medium and low-carbon alloy constructional steel workpiece into a solid solution nitrogenation furnace which is shown in the patent having a patent name of pressurization high-temperature nitridation device with dual pressure equilibrium structure and having the patent number of 201210530358.6, improving the pressure to 0.1-0.5MPa at a temperature of 500-800 DEG C, feeding NH3 into the solid solution nitrogenation furnace at a flow rate of 0.1-0.5L/min, carrying out gas nitridation treatment at a decomposition rate of 30-80% for 5-20 hours, sequentially feeding NH3 into the solid solution nitrogenation furnace, cooling to a temperature below 150 DEG C, and taking out the workpiece. The medium and low-carbon alloy constructional steel surface pressurization gas-nitridation method can effectively promote adsorption of N atoms on the part surface, improve N activity, an interface reaction rate and a hole and slit nitridation capability, reduce an NH3 decomposition rate, improve nitrogen potential, obviously reduce an NH3 consumption amount in nitridation, greatly improve process effects and realize short-term deep nitridation.

The invention discloses 38CrMoAl nitrided steel with a nitrided layer low in fragility and belongs to the technical field of alloy steel. The 38CrMoAl nitrided steel with the nitrided layer low in fragility comprises, by mass, 0.35%-0.42% of carbon, 0.20%-0.45% of silicon, 0.30%-0.60% of manganese, 1.35%-1.65% of chromium, 0.15%-0.25% of molybdenum, 0.70%-1.10% of aluminum, 0%-0.015% of phosphorus, 0%-0.010% of sulphur, 0.001%-0.01% of vanadium, 0.001%-0.01% of niobium, 0.001%-0.01% of titanium, 0.0020%-0.006% of nitrogen, 0.0005%-0.0025% of oxygen and the balance iron and other inevitable impurities. The 38CrMoAl nitrided steel with the nitrided layer low in fragility has the advantages that under the same nitriding process, the fragility of the nitrided layer can be reduced, and production cost and use cost are not increased obviously.

The invention discloses a non-brittle nitridation technique for bearing components. According to the technological process, whether the interior of a nitridation furnace leaks air or not is detected firstly, if the air is not leaked, the inflation stage is executed, and then the temperature in the nitridation furnace is increased to 300-350 DEG C; ammonia gas and mixed liquid of a penetrating agent and ammonium chloride concentrated liquid are led into the nitridation furnace, the leading-in speeds of the ammonia gas and the mixed liquid of the penetrating agent and the ammonium chloride concentrated liquid are controlled, and the interior of the furnace continues to be heated till the temperature is 480-500 DEG C; then the leading-in speeds of the ammonia gas and the mixed liquid of the penetrating agent and the ammonium chloride concentrated liquid are increased, and the temperature of the interior of the furnace is increased to 520-550 DEG C; then the inflation speed of the ammonia gas is decreased, and leading-in of the ammonia gas and the mixed liquid of the penetrating agent and the ammonium chloride concentrated liquid is stopped; gas in the furnace is discharged, the pressure in the furnace is controlled, and the temperature in the furnace is decreased to 100-130 DEG C; and finally an ammonia gas bottle and a nitridation furnace gas inlet valve are closed, vacuumizing is conducted, nitrogen gas is led into the furnace to enable the pressure of the interior of the furnace to be positive, the valve is opened, air in the furnace is replaced, the temperature is decreased, and the components are taken out. According to the non-brittle nitridation technique for the bearing components, the problems that as for an existing nitridation technique, the depth of the effective nitridation layer is small, the surface hardness is low, and deformation is large can be effectively solved.

The invention discloses a magnesium smelting technique by microwave heating and relates to the field of magnesium smelting techniques. The upper end of the round wall of a furnace body is connected with an expander by bricklaying through a refractory material, and the lower end of the round wall of the furnace body is fixed with a tray; the expander is movably connected with a support in a sliding manner; the lower end of a microporous ceramic tube is fixed with the tray while the upper end of the microporous ceramic tube is fixed with the support; the furnace body is fixed with a microwave generator and a shell; the shell is fixed with an upper flange and a lower flange; a gaseous magnesium collecting chamber is formed by the wall of the furnace body above the support, an upper convergent section of the shell and the inner side of the upper flange; a gaseous magnesium outlet tube is penetrated from the gaseous magnesium collecting chamber and then is fixed with the furnace body and the shell; a slag chamber is formed by the wall of the furnace body below the tray, a lower convergent section of the shell and the inner side of the lower flange; a magnesium ball is put in the microporous ceramic tube; slag is put in the slag chamber; the power of the microwave generator is 1-500KW, the frequency of the microwave generator is 300-3000MHz, the temperature of the microwave generator is 1200-1350 DEG C, and the smelting time is 15-60 minutes; the magnesium ball is acquired by roasting dolomite to acquire magnesium oxide and calcium oxide and then mixing silicon iron and fluorite with magnesium oxide and calcium oxide. The magnesium smelting technique by microwave heating is used for smelting magnesium, which is a microwave new energy heating technology.

The invention discloses a metal surface nitriding technology. The metal surface nitriding technology involves a to-be-processed metal workpiece, and processing of the workpiece comprises the followingsteps of carrying out immersion cleaning on the workpiece with water containing detergent, carrying out immersion cleaning on the workpiece with water at 100 DEG C after the workpiece is washed withclear water, and placing the oil stain-removed workpiece into a pool for ultrasonic cleaning, wherein the cleaning vibration frequency is 80-160 KHz, the power density is set at 0.6-1.0 W/C, the workpiece is preheated to 300-385 DEG C, and the preheating time period is 6-25 minutes; placing the workpiece in a nitriding furnace containing base salt containing Li ions, raising the temperature of thenitriding furnace to 520-580 DEG C, wherein the nitriding time period is 80-100 minutes; and adding sodium peroxide solid into the base salt, wherein the weight ratio of the solid sodium peroxide tothe base salt is 1 to 2.5-4.5. According to the technology, by adding ultrasonic cleaning, in the process of cleaning the workpiece, a strong cleaning effect on the workpiece can be rapidly realized,so that solid dirt on the surface of the workpiece is separated from the workpiece, and the nitriding effect can be effectively improved in the nitriding process.

The invention discloses a dental plate surface nitriding technology, and relates to the technical field of workpiece nitriding treatment. The technology comprises the steps of 1) preparing before treatment, 2) vacuumizing, 3) heating, 4) reheating, 5) vacuumizing, 6) surface activating, 7) vacuumizing, 8) decomposing through ammonia gas, 9) nitriding, 10) vacuumizing, 11) blackening, and 12) cooling. The technology has the beneficial effects that the fatigue resistance of a workpiece is improved; high pressure stress is generated in a nitriding layer, so that the fatigue limit of the workpieceis high, and the sensitivity of the workpiece is low under the effect of alternating load; and moreover, the fatigue limit of the workpiece subjected to alternating load can be increased by 200%.

Novel three-section nickel-based screw-grinding waste plastic modification regeneration energy-saving equipment relates to the technical field of plastic machinery and is mainly composed of two parts, namely a working part and a base support. The main body of the working part is a heating fusion tube, inside which three sections of grinding mechanisms are arranged. A filament extrusion mechanism is connected to the right end of the heating fusion tube. A cooling device is disposed at the lower end of the filament extrusion mechanism. The base support part mainly comprises a pedestal and an engine and a speed change gear box which are arranged on the pedestal. The engine is connected with the speed change gear box through a transmission shaft. The speed change gear box is connected with the heating fusion tube. The three sections of grinding mechanisms contain a charging barrel and a screw arranged in the charging barrel. Thread of the screw is provided with a trough of 12mm width and 1.5mm depth. A nickel-based ceramic alloy powder is sprayed in the trough. By a three-section twin-exhaust grinding technology, a waste plastic raw material is fully heated and ground. Grinding fineness of waste plastic reaches 40-60 nanometers or molecular state; first pass yield reaches 98%; and energy consumption is saved by more than 46%.

The invention discloses an atmospheric supersonic-speed plasma spraying device capable of forming a shielding gas hood. The atmospheric supersonic-speed plasma spraying device capable of forming the shielding gas hood comprises an anode nozzle, wherein the anode nozzle is in the shape of a rotating body and is provided with a central through hole. The anode nozzle is further provided with a shielding gas hole and a powder feeding hole, wherein the inlet end of the shielding gas hole is arranged on the circumferential surface of the anode nozzle, the outlet end of the shielding gas hole communicates with the central through hole, and an acute angle alpha is formed between the axis of the shielding gas hole and the axis of the central through hole; and the inlet end of the powder feeding hole is arranged on the circumferential surface of the anode nozzle, the outlet end of the power feeding hole communicates with the central through hole, and the axis of the powder feeding hole is perpendicular to the axis of the central through hole. The atmospheric supersonic-speed plasma spraying device capable of forming the shielding gas hood is simple in structure and is not provided with a solid hood, a cold water device does not need to be additionally arranged, and mounting, dismounting and checking are convenient; and sprayed materials are not prone to adhering to a duct of a nozzle, jet flow and the atmospheric environment are isolated to a certain extent by shielding gas, oxidation of sprayed particles in the jet flow can be reduced, the jet flow is cooled to a certain extent, the temperature of the jet flow and the temperature of the sprayed particles are decreased accordingly, and the probability of oxidation of the sprayed particles is lowered.

The invention discloses an atmosphere supersonic speed plasma spraying device with two-section type protection air holes. The spraying device comprises an anode nozzle. The front end of the anode nozzle is cylindrical, and a center through hole is formed in the anode nozzle. The anode nozzle is further provided with the protection air holes and powder feeding holes. The inlet ends of the protection air holes are arranged on the circumferential face of the anode nozzle, and the outlet sections of the protection air holes are arranged on the front end face of the anode nozzle. The protection air holes comprise the first section of air holes and the second section of air holes. The axis of the first section of air holes and the axis of the center through hole form an acute angle of alpha, and the axis of the second section of air holes and the axis of the center through hole form an acute angle of beta. The inlet ends of the powder feeding holes are arranged on the circumferential face of the anode nozzle, and the outlet ends of the powder feeding holes communicate with the center through hole. In addition, the axis of the powder feeding holes is perpendicular to the axis of the center through hole. The atmosphere supersonic speed plasma spraying device is simple in structure, a solid cover is omitted, and additional arrangement of a cold water device is needless. Mounting, dismounting and inspection are convenient, the temperature of jet flow and the temperature of spraying particles can be lowered, and oxidization probability of the spraying particles is reduced.

The invention relates to the technical field of metallurgy, and provides a preparation method of a VN19 vanadium-nitrogen alloy. According to the preparation method, powdery vanadium oxide, silicon dioxide powder, a carbonaceous reducing agent, iron powder and a binder are mixed and then sequentially subjected to ball pressing, drying, vacuum carbonization reduction and nitridation, and the VN19 vanadium-nitrogen alloy is obtained. The silicon dioxide powder is added into the raw materials, the silicon dioxide powder is reduced, and silicon nitride is generated in the nitriding process, so that the nitrogen content of a product is increased. According to the preparation method, carbonization reduction is carried out under the vacuum condition, nitridation is carried out under the high nitrogen pressure, and the VN19 vanadium-nitrogen alloy can be efficiently and rapidly prepared in an energy-saving mode. Furthermore, the trend of nitrogen gas flow in the nitriding process is optimized, and a weak cooling and strong cooling subsection cooling mode is adopted in the cooling process, so that the nitrogen content of the product is increased, heat energy is fully utilized, and the preparation cost is reduced.

The invention provides a modified nickel cobalt lithium manganate ternary positive electrode material as well as a preparation method and application thereof. The preparation method of the modified nickel cobalt lithium manganate ternary cathode material comprises the following steps of preparing a braided spherical nickel cobalt lithium manganate ternary material; carrying out first ball-millingmixing treatment on the nickel cobalt lithium manganate ternary material powder and a rare earth nitride and lithium nitrogen mixture to obtain mixture powder; and carrying out segmented sintering treatment on the mixture powder in a nitrogen-oxygen mixed atmosphere. According to the preparation method of the modified lithium nickel cobalt manganese oxide ternary positive electrode material, the ternary material particles are coated with the rare earth nitride and lithium nitrogen mixture, so that the capacity exertion and the cycle retention rate of the ternary material are effectively improved, the nitridation effect of the ternary material is improved, and the lithium-nickel mixed arrangement of the material and the redundant lithium on the surface of the material are better relieved. Meanwhile, the nitride coating layer reduces and prevents the contact between the electrolyte and the active material, reduces the irreversible side reaction, and reduces the formation of a solid electrolyte membrane (SEI).