98results about How to "Remarkable grain refinement effect" patented technology

The invention relates to a high-speed steel roll and a preparation method thereof by centrifugal compounding in an electromagnetic field, belonging to the technical field of preparation of the high-speed steel roll. The components of a working layer material of the high-speed steel roll are as follows (in weight percent): 1.5 to 2.5 percent of C, 4.0 to 6.0 percent of V, 4.0 to 6.0 percent of W, 1.5 to 4.5 percent of Mo, 2.0 to 4.0 percent of Cr, 0.04 to 0.18 percent of Zr, 0.001 to 0.003 percent of B, less than or equal to 0.5 percent of Si, less than or equal to 0.5 percent of Mn, and the balance of Fe and impurity elements; and in the impurity elements, the required contents of S, P and O are respectively less than 0.01 percent, less than 0.01 percent and less than 0.0010 percent. The roll is cast by adopting a centrifugal compounding method in a pulse electromagnetic field, the frequency of the pulse magnetic field is 0.1 to 10Hz, and the peak strength of a central magnetic field of a cast mold is 1 to 10T. The roll has a plurality of precipitation strengthening phases, and the applied pulse magnetic field leads the strengthening phases and matrix crystal grains to be refined effectively and leads the strengthening phases to be distributed in a dispersed manner, thus overcoming the segregation of alloy elements and greatly improving the performance of the roll.

The invention provides a method for preparing a nanocrystalline austenitic stainless steel plate through deep cooling rolling-rapid annealing and belongs to the field of stainless steel manufacturing. The method comprises the steps that (1) an austenitic stainless steel blank is hot-rolled after being subjected to heat preservation at the temperature of 1150 DEG C-1250 DEG C and then is air-cooled to the room temperature after being water-cooled to 150 DEG C-200 DEG C, and a hot-rolled plate is prepared; (2) deep cooling rolling is conducted, specifically, the hot-rolled plate is subjected to solid solution treatment, after an oxide layer on the surface is removed, deep cooling rolling is conducted, the steel plate is subjected to liquid nitrogen treatment before cold rolling per pass, and a deep cooling rolled stainless steel plate is prepared; and (3) the deep cooling rolled stainless steel plate is air-cooled to the room temperature after being subjected to heat preservation at the temperature of 600 DEG C-850 DEG C, so that the nanocrystalline austenitic stainless steel plate is prepared. The yield strength of the stainless steel plate prepared by the method is 956-1170 MPa, the tensile strength is 1130-1380 MPa, the percentage elongation after fracture is 18%-52%, and the product of strength and elongation is 55000-58080 MPa.%. According to the method for preparing the nanocrystalline austenitic stainless steel plate through deep cooling rolling-rapid annealing, the time is short; the efficiency is high; energy sources are saved; the cost is low; and a sample piece large in section size is easy to produce.

The invention relates to a semisolid alloy preparation method, in particular a method for preparing a spherical primary crystal semisolid alloy through centrifuging and chilling. The method comprises the following steps of: first, melting the alloy to a certain temperature; and then pouring the melt in a centrifugal barrel; throwing the melt to the inner wall of a chilling barrel after rotating the melt through centrifugal force; carrying out mixed convection on the melt in the centrifugal barrel under the double effects of centrifugal force and chilling force; and finally, obtaining a non-dendritic semisolid alloy blank or slurry with spherical or granular primary phase under the mutual effect of numerous nucleation and dendrite breaking of the outer barrel. The method for preparing the spherical primary crystal semisolid alloy through centrifuging and chilling, provided by the invention, has the characteristics of simple equipment, high production efficiency, wide application range of alloy, fine and rounded primary phase with semi-solid structure and the like, and can be used for the preparation and molding production of the metal semisolid alloy.

The invention discloses a blocked type variable cross-section reciprocating squeezing, twisting and upsetting forming method for ultra-fine grain bars. On the basis of a three-way hydraulic forming machine, the die assembly force is provided through an upper slide block, and pressure required for forming of punches at the two ends is provided through a left slide block and a right slide block. A die inner cavity is a linear channel formed by sequentially connecting a first squeezing channel, a middle twisting channel and a second squeezing channel on the same straight line. The section area of the middle twisting channel is smaller than the section area of the first squeezing channel and the section area of the second squeezing channel. The punches at the two ends are located at the two ends of the linear channel in a one-to-one correspondence manner, and a blocked variable section cavity is formed through the reciprocating punches at the two ends. By means of reciprocating of the punches at the two ends, the reciprocating squeezing, twisting and upsetting process of a to-be-processed blank in the linear channel is achieved, and preparation of the ultra-fine grain bars is completed through multi-pass forming. By means of the blocked type variable cross-section reciprocating squeezing, twisting and upsetting forming method, bar grains can be effectively refined, the forming limit of the bars is improved, and the blocked type variable cross-section reciprocating squeezing, twisting and upsetting forming method is easy to operate, high in applicability and capable of being easily applied in an engineered manner.

A method for preparing nanocrystalline magnesium alloy powder relates to the preparing method of magnesium alloy powder, which solves the problem that the machinery method prepares the powder with long time of ball milling, easy oxidation and low producing efficiency. In the fast solidify method for preparing the powder, only a very few magnesium alloy with exceptive alloy ingredient can obtain the nanocrystalline due to limit by thermodynamics condition. For most of magnesium alloy, crystal grain only can be refined to a range from 1 um to 3 um. The method of the invention is that magnesium alloy ingot is crushed to rough power, the rough power of the first step is put into a goal agate jar, the goal agate jar is vacuum and charged with hydrogen, the rough power is rub with machine in full hydrogen condition and the hydride state nanocrystalline magnesium alloy powder is dehydrogenated in vacuum by heating to get the nanocrystalline magnesium alloy powder material. The invention integrates the hydrogen processing and the machine goal agate method, therefore, the effect of crystal grain refinement is prominent and nanocrystalline is quickly obtained. The invention has the advantages of good thermal stability of hydride state powder, even organization and uneasy oxidation.

The invention discloses a high-temperature alterant, which comprises the following components in percentage by weight: 15 to 20 percent of chloride, 40 to 45 percent of chloride, 25 to 30 percent of rare earth metal compound, 3 to 8 percent of titanium dioxide, and 2 to 6 percent of graphite. The invention also discloses a method for purifying a fusant, wherein the high-temperature alterant is added into a smelting furnace. The high-temperature alterant can reduce the sodium content in an electrolytic molten aluminum fusant and effectively control the grain size to achieve good grain refining effect. The method for purifying the fusant can effectively reduce gas and foreign impurities in the fusant, optimize the production process, ensure the quality of aluminum and aluminum alloy fusants, improve the ingot yield, save the energy consumption, and reduce the discharge of pollutants.

The invention discloses a high-strength corrosion-resistant AL-Mg alloy. The high-strength corrosion-resistant AL-Mg alloy comprises the following chemical components in percentage by weight: less than or equal to 0.3% of Fe, less than or equal to 0.25% of Si, less than or equal to 0.1% of Cu, 0.4-1.2% of Mn, 4.5-6.0% of Mg, 0.25-0.55% of Zn, 0.10-0.3% of Cr, less than or equal to 0.15% of Zr, less than or equal to 0.15% of Ti, and the balance of Al. The high-strength corrosion-resistant AL-Mg alloy solves the problems that the strength and the corrosion resistance of the conventional aluminum alloy 5083 in the manufacturing of a traffic tool are not good, the tensile strength of the obtained alloy sigma b is more than or equal to 320Mpa, the yield strength sigma 0.2 is more than or equal to 160 Mpa, the ductility delta is more than or equal to 23%, and the grade of an exfoliation corrosion test reaches PA level.

The invention relates to the technical field of metal surface cladding materials, and in particular relates to a steel wire hot dipping rare earth zinc alloy and a hot dipping method. With the method, the hot dipping alloy is adopted to carry out hot dipping on steel wires, and a pulsed magnet field is applied to a hot dipping alloy molten pool in the hot dipping process. The hot dipping alloy comprises the following components in percentage by mass: 0.02-0.06% of rare earth mixture 1 or rare earth mixture 2, 4.0-4.5% of Al, 0.11-0.2% of Ti, 0.05-0.10% of B, 0.01-0.05% of Sr and the balance of Zn and inevitable impurities, wherein the rare earth mixture 1 is composed of at least two of rare earth Ce, La and Pr at the mass ratio of 1:1, and the rare earth mixture 2 is composed of rare earth Ce, La and Pr at the mass ratio of 1:1:1. The parameter range of the pulsed magnet field is that the pulse width is 80-100ms, the action frequency is 1-2Hz, and the peak value intensity of the pulsed magnet field is 11-15T. According to the steel wire hot dipping rare earth zinc alloy, the clapping material quality is improved, and the consumption of rare earth and other metals is saved. The technology applied in the method is simple, and the existing technical equipment is mature, has low cost and is worthy of popularization.

The invention discloses an aluminium calcium carbon grain refiner for Mg-Al series magnesium alloy and a preparation method and application thereof. The grain refiner provided by the invention comprises aluminium, calcium, carbon and magnesium; and by adding the aluminium calcium carbon grain refiner to magnesium alloy melt, fine heterogeneous phase particles, i.e. Al4C3, supply a large number of effective heterogeneous nucleation cores, Ca solute released by dissolved CaA12 (or CaAl4) particles restrains the growth of magnesium alloy grains, and the casting-state magnesium alloy grains are obviously refined and increased in terms of strength and plasticity under the composite refining effect. The grain refiner provided by using the method is a metal block and is convenient to add in the magnesium alloy melt; the addition amount and the component content of the grain refiner are easily controlled; and the purpose of high efficiency refinement can be achieved by adding a trace of grain refiner.

The invention discloses an equal-channel corner revolving extrusion die and method and belongs to the field of material machining. The die comprises bolts and die sections, bolt holes are respectively and correspondingly arranged in the two die sections, and the two die sections are fastened with the bolts. Parting surfaces of the two die sections cling to each other completely to form a structure with the center being an extrusion cavity of the die, the extrusion cavity is an equal-channel corner extrusion die cavity, and the equal-channel corner extrusion die cavity is sequentially provided with a die cavity leading-in section, a die cavity leading-in transition section, a die cavity corner section, a die cavity leading-out transition section, a die cavity leading0out section and a die cavity taking-out section. The equal-channel corner revolving extrusion die has the advantages of high grain refining capability, convenience in operation, simple structure and continuous extrusion.

The invention discloses a method for improving mechanical properties of 301LN austenitic stainless steel and belongs to the stainless steel preparation field. According to the method, a 301LN austenitic stainless steel blank which is 40-60 mm thick is subjected to hot rolling till a plate which is 4-5 mm thick is obtained; then cold rolling-annealing process treatment is performed; and the 301LN austenitic stainless steel with the yielding strength ranging from 700 MPa to 1000 MPa, the tensile strength ranging from 1000 MPa to 1200 MPa and the ductility larger than 30% is prepared. The method is easy to operate, and industrial production can be achieved conveniently.

The invention discloses an Al-TiO2-C grain refiner, a preparation method thereof and a commercial-purity aluminum refining method. The Al-TiO2-C grain refiner is composed of Al powder, TiO2 powder and C powder. The preparation method of the Al-TiO2-C grain refiner comprises the steps that 1, the Al powder, the TiO2 powder and the C powder are mixed and then processed on a star type ball mill through ball milling for 0.5-2 h; 2, a precast block with the diameter phi being 30 is pressed on a universal tester, wherein 85 KN pressure is used for block pressing; 3, the precast block is wrapped by aluminum foil, and air between the precast block and the aluminum foil is extruded for storage; 4, the precast block is sintered in a high-temperature sintering furnace; and 5, furnace cooling is carried out, then the sintered precast block is taken out, and therefore the prepared Al-TiO2-C grain refiner is obtained. Precipitated phases of the prepared Al-TiO2-C grain refiner are TiC, Al2O3 and Al3Ti phases. The Al-TiO2-C grain refiner has the good grain refining effect. By adjusting the ratio of C to TiO2, the TiO2 addition, pressure needed for precast block preparation and the like, Al2O3 with the appropriate amount is contained in the Al-TiO2-C grain refiner structure and distributed in a relatively dispersed mode, and the better grain refining effect is achieved.

The invention discloses a grain refiner for ferritic stainless steel continuous casting. The grain refiner comprises, by weight percentage, 0.01%-0.05% of TiC powder and 99.95%-99.99% of pure Fe powder; the grain size of the TiC powder is smaller than 1 micrometer, the grain size of the pure Fe powder ranges from 10 micrometers to 20 micrometers, and the density of particles of the TiC powder in the grain refiner is larger than 20000 units/mm<3>. The preparing method of the grain refiner includes the following steps that (1) material grinding is carried out, wherein large-particle TiC prepared through a carbon thermal reduction process is placed into a planetary mill to be ground, grinding is carried out until the mean grain size is smaller than 1 micrometer, and micron order TiC powder is obtained; (2) even mixing is carried out, wherein the obtained micron order TiC powder and the pure Fe powder with the grain size ranging from 10 micrometers to 20 micrometers are weighed according to the weight percentages of the raw materials to be placed into a ball mill for even mixing; and (3) hot isostatic pressure molding is carried out, wherein mixed powder obtained after even mixing in the step (2) is subject to hot isostatic pressure molding. During ferritic stainless steel continuous casting production, the grain refiner is added, the proportion of columnar crystals of a ferritic stainless steel continuous casting blank is greatly reduced, the isometric crystal proportion is improved to 70% or above, and the grain refinement effect is remarkable.

The invention provides a spiral tapered roll type equal-roll-spacing rolling method of a large-size ultrafine aluminum alloy crystal bar, and relates to the technical field of mechanical processing. The method comprises the steps of S1, selecting an aluminum alloy blank of which the diameter D is 40-200nm and the length is 300-5000mm; S2, feeding the aluminum alloy blank into a heating furnace, and heating to reach the temperature of 380-450 DEG C; S3, transferring the heated aluminum alloy blank from the heating furnace into a material guide groove of a skew rolling mill; S4, feeding materials into the material guide groove of the skew rolling mill; feeding the aluminum alloy blank between a deformation area between an inlet and an outlet of the skew rolling mill; and spirally moving thealuminum alloy blank in the deformation area until the deformation is finished; and S5, repeating the steps S2-S4; and spirally rolling the aluminum alloy blank in 2 to 14 times to obtain an integralultrafine aluminum alloy bar. The method has the beneficial effects that the deformation area is high in penetration depth; and the rolling can be performed in a plurality of times in a reciprocatingmanner; the local deformation is continuously stably performed; the pressing-twisting combined three-dimensional severe deformation is carried out; and ideal grain refining effect is obtained.

The invention discloses a reciprocating twisting and upsetting isometric angle forming method for preparing an ultra-fine grain material. Based on a multi-station forming hydraulic machine, a combinedfemale die is adopted as the die, wherein an upper die and a lower die of the combined female die are split. An upper sliding block in the multi-station forming hydraulic machine is used for providing die combining force needed by the combined female die, and a die inner cavity of the combined female die is formed by sequentially connecting a left-side extruding channel, a twisting channel, a right-side extruding channel and an isometric angle extruding channel. Due to the fact that a left-side hydraulic cylinder located at the inlet end of the left-side extruding channel and a right-side hydraulic cylinder located at the inlet end of the isometric angle extruding channel are used for providing extruding force and back pressure force in turns. The right-side hydraulic cylinder is arrangedon an arc sliding rail, the position of the right-side hydraulic cylinder in the arc sliding rail is adjusted so that the set angle of the isometric angle extruding channel can be obtained. By meansof the reciprocating twisting and upsetting isometric angle forming method, the grain structure of the material can be refined to the ultra-fine grain level, the material strength and plasticity are obviously improved, the application range is wide, operation is easy and convenient, and industrial application is easy to achieve.