52results about How to "Shorten nitriding time" patented technology

The invention provides an ionic nitriding technology assisted by an arc electron source. The ionic nitriding technology assisted by the arc electron source comprises the steps that S1, vacuumizing iscarried out; S2, preheating is carried out; S3, mechanical corrosion is carried out, specifically, argon is pumped to keep vacuum of 0.1-1Pa, the temperature is 200-600 DEG C, a bias voltage is applied between a workpiece and a cavity body, meanwhile, a furnace inner arc electron source is started, a main power supply current is 40-150 A, and arc discharge plasma is generated; an auxiliary anode electrode power supply is turned on, a current is 10-100 A, an electron current in the arc discharge plasma is led to enter a nitriding chamber space, and ironic bombardment mechanical corrosion is carried out on the workpiece for 5-30mins; S4, nitriding is carried out, the furnace inner temperature is kept 200-600 DEG C, the argon and nitrogen are pumped, the vacuum degree is kept at 0.1-1Pa, a voltage is applied between the workpiece and the cavity by a direct current bias voltage power supply, the arc electron source main power supply is turned on, the current is 40-150 A, and the arc discharge plasma is generated; the auxiliary anode electrode power supply is turned on, the current is 10-100A, the electron current of the arc discharge plasma is led to enter the nitriding chamber space,and ironic nitriding is carried out for 0.5-6 hours; and S5, cooling is carried out below 250 DEG C. According to the ionic nitriding technology assisted by the arc electron source, a glow discharge plasma can be enhanced, the reactivity is improved, time is shortened, and gas and energy consumption are reduced.

The invention relates to a method for local ion nitriding of a deep cavity thread of a titanium alloy part, and belongs to the technical field of chemical heat treatment. The method comprises the steps of 1, manufacturing a nitriding tool according to the size and shape of the titanium alloy part; 2, carrying out vacuum annealing treatment on the nitriding tool; 3, wiping the titanium alloy part and the nitriding tool, and blow-drying the titanium alloy part and the nitriding tool through oil-free compressed air or nitrogen; 4, coating the outer wall of the titanium alloy part with the nitriding tool; 5, repeating the step 1 to the step 4 for n times, manufacturing n nitriding tools for coating the titanium alloy part, and enabling the n nitriding tools to be annularly and evenly arrangedon an ionization disc, wherein n is a positive integer; and 6, conducting nitriding treatment on the titanium alloy part. According to the method, the outer surface of the part and the non-nitrided part of the deep cavity are protected against a nitriding layer through tool design, and the temperature, time, atmosphere and electric parameters in the nitriding process are adjusted, so that the whole deep cavity thread obtains the hardness and nitriding depth of the nitriding layer meeting the technical requirements.

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 provides a rapid nitriding process, and belongs to the technical field of heat treatment. The rapid nitriding process includes: a step A that an electrolyte is added to an electrolysis container, the electrolysis container is then sealed, an electric heating device is arranged on the side portion of the electrolysis container, and a natural gas heating device is arranged at the bottom of the electrolysis container; a step B that external ammonia gas is sent to a gas outlet pipe through a valve, the whole electrolysis container and a whole nitrogenation oven are filled with the ammonia gas in a circulating mode, and then the valve is closed; a step C that a controller controls the natural gas heating device to heat the electrolyte to the boiling point, and then the controller drives an electrolysis rod to work and conduct electrolysis; a step D that the controller controls the natural gas heating device and the electric heating device to conduct alternative heating so that the concentration of nitrogen atoms can be increased; and a step E that an air blower is started so that the ammonia gas and the generated nitrogen atoms can be mixed in water vapor and unceasingly sent to the nitrogenation oven, and closed type circulation is achieved through cooperation of the gas outlet pipe and a gas inlet pipe. Thus, the nitrogen atoms in the nitrogenation oven can be unceasingly supplemented, the nitridation time can be shortened by half, and the defect that the cost is high due to the fact that ammonia gas is unceasingly conveyed in the conventional process is overcome.

The present invention is surface treatment process for cylinder jacket of steel, and belongs to the field of diesel engine accessory making technology. The surface treatment process for cylinder jacket of steel features the soft gas nitridizing process or carbonitriding process. The present invention has reasonable design, and is smart, simple and feasible. The present invention can form one nitride layer with thickness of 0.1-0.4 mm, hardness up to HV600-700, and capacity of raising the mechanical performance and wear resistance of the cylinder jacket, increasing its service life and raising the piston ring matching performance.

The invention discloses a QPQ salt bath nitriding optimization treatment method through laser shock peening. The QPQ salt bath nitriding optimization treatment method comprises the following steps that shock peening treatment is conducted on a workpiece by using a laser device to enable the surface of the workpiece to be dislocated; the workpiece is deoiled, cleaned and dried; the workpiece is putinto a preheating furnace for preheating; the workpiece is put into a direct-current electric field salt bath nitriding furnace, wherein the temperature in the furnace is 500-580 DEG C; the temperature is reduced to 400-450 DEG C for oxidation treatment, and the workpiece is taken out to be cleaned so as to remove CN<-> or CNO<->; the surface of the workpiece is polished; the workpiece is put into the direct-current electric field salt bath nitriding furnace, oxidation treatment is conducted on the workpiece again at the temperature of 300-400 DEG C, and the workpiece is cleaned to remove CN<-> or CNO<->; drying is conducted; and oil immersion is conducted. Compared with the prior art, the QPQ salt bath nitriding optimization treatment method has the advantages that the nitriding efficiency and the nitriding layer thickness are improved, and energy conservation and high efficiency are realized. The invention further provides a QPQ salt bath nitriding optimization treatment device.

The invention discloses a preparation method of aluminum nitride powder. The preparation method comprises the following steps of: mixing aluminum nitrate, calcium nitrate, acetylene black and polyethylene glycol, dissolving in deionized water, uniformly stirring and mixing, heating to 65-75 DEG C, adding urea, dropwise adding an ammonia water solution, heating and keeping for 20-40 minutes, putting into a 1250 DEG C heating furnace, and keeping the temperature for 1-2 hours in a nitrogen atmosphere to obtain a precursor; mechanically mixing the precursor; putting the mechanically mixed precursor into a microwave high-temperature sintering furnace, and carrying out nitriding treatment to obtain carbon-containing aluminum nitride; and putting the carbon-containing aluminum nitride into a decarburization furnace for decarburization so as to obtain aluminum nitride powder. The prepared aluminum nitride powder has the characteristics of uniform particle size distribution, small particle size, high purity and low impurity oxygen content, the preparation method is simple, the preparation process is easy to operate, and the aluminum nitride powder is suitable for large-scale production andprocessing.

The invention discloses a production method for nitrided ferrochromium. The method comprises the steps as follows: (1) lump extra-low-carbon ferrochromium is crushed into fine particles with the particle size small than or equal to 2 mm; (2) nitrogen with the purity higher than 99.999% is introduced into a microwave pushed slab kiln, oxygen in the kiln is exhausted until the oxygen content in the kiln is lower than 100 ppm, and the air pressure in the kiln is kept at 100 KPa-100.1 KPa; (3) crushed raw materials are placed in a mullite sagger containing 5%-80% of silicon carbide, a pure silicon carbide sagger or a silicon carbide and silicon nitride combined sagger; and (4) the materials are preheated, nitrided, melted, sintered, cooled and discharged sequentially in the microwave pushed slab kiln. According to the production method, the nitriding and sintering temperature is low, the product quality is stable, and the nitrogen content is high; the industrial microwave pushed slab kiln has high degree of automation, can perform continuous production and has low operation and maintenance cost; the producing cycle is remarkably shortened by more than 30%; and energy conservation and emission reduction are achieved, and the production environment is clean.

The invention discloses a preparation method of alpha-silicon nitride powder, which comprises the following steps: carrying out ball milling on silicon powder doped with Cr2O3 powder, adding a siliconnitride grinding ball and alcohol; putting the silicon powder into a ball mill for ball milling, carrying out suction filtration on the ball milled Cr2O3 silicon powder, and removing the alcohol in the silicon powder; drying the filtered powder in a vacuum drying oven, and removing residual alcohol; grinding and sieving a sample subjected to vacuum drying to obtain powder with uniform particles;putting the ground silicon powder doped with Cr2O3 into a high-temperature tubular furnace, vacuumizing, introducing a nitrogen-hydrogen mixed gas, raising the temperature to 800 DEG C at less than orequal to 5 DEG C/min, and raising the temperature to 1300-1400 DEG C/min, keeping the temperature for 2-4 hours to obtain the silicon nitride powder. The preparation method has the advantages of lownitriding temperature, low cost and short nitriding period, wherein the prepared alpha-Si3N4 phase is as high as 96 wt% in the prepared power, and the particle size is small, and part of the Si3N4 phase is fibrous.

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 an energy saving and rapid ion nitriding technology for an alloy steel worm. The technology includes the steps of: first, conducting ultrasonic cleaning on an alloy steel worm workpiece to remove oil stain from the surface of the alloy steel worm workpiece; second, loading the workpiece into an ion nitriding furnace, and then pumping the ion nitriding furnace into a vacuum state; third, powering on the ion nitriding furnace, conducting vacuum pumping to make the furnace pressure lower than 150Pa, introducing 500-600V direct current voltage for arc striking, and performing plasma bombardment on the workpiece surface to remove surface oil stain; fourth, conducting heating to 350DEG C; fifth, introducing a certain amount of air, and performing heat preservation for 2h;sixth, introducing ammonia gas for ion nitriding on the workpiece surface; and seventh, conducting cooling. The technology provided by the invention can save the overall nitriding time by 6h, and shorten the time by 20%, and saves 20%-25% of electric energy and ammonia gas.

The invention relates to a method for continuously producing a manganese nitride product, which comprises the following steps of: crushing electrolytic manganese sheets, manganese metal and ferromanganese, pressing and forming, placing the pressed and formed material in a pushed slab kiln or a tunnel kiln, introducing nitrogen or ammonia-nitrogen mixed gas into the pushed slab kiln or the tunnel kiln, and continuously producing the manganese nitride product. And heating in a pushed slab kiln or a tunnel kiln to 700-1000 DEG C to produce a manganese nitride product. The method has the advantages of no need of vacuumizing, continuous production, low energy consumption, small equipment investment, high production efficiency, short production time and the like. The nitrogen content of the obtained manganese nitride product is about 7-8wt%.