54results about How to "Increase solid solution" patented technology

A hot-rolled ribbed steel bar having a strength-to-yield ratio of 1.25 or more comprises 0.17-0.25wt% of C, 0.4-0.8wt% of Si, 1.2-1.5wt% of Mn, 0.045wt% or less of P, 0.045wt% or less of S, 0.05-0.08wt% of V, 0.006-0.018wt% of N, and the balance of Fe and impurity elements, and has a specification diameter of 12-40mm. A production method of the hot-rolled ribbed steel bar comprises the following steps: desulfurizing molten iron; carrying out top-bottom blowing of a converter; carrying out component fine-adjustment at an argon station, and blowing in nitrogen; refining an LF furnace, and blowing nitrogen into the LF furnace; continuously casting; carrying out stacking cooling; heating casted blanks; carrying out rough rolling and finish rolling; and naturally cooling to room temperature. Nitrogen is blown to realize greatly reduced cost, greatly reduced vanadium alloy consumption, increased V (C,N) amount and dispersity with the increase of the content of N in steel, substantial reinforcement effect and stable mechanical performances on the premise that mechanical performances comprising a hot-rolled yield strength of above 530MPa, a strength-to-yield ratio of 1.25-1.30, an A value of 18% or more and an Agt value of 10 or more are guaranteed.

The invention provides a high-strength and high-conductivity Cu-Cr-Nb alloy with a double-peak grain size and a double-scale nano-phase reinforcing function, and belongs to the field of additive manufacturing and high-strength and high-conductivity copper alloys. In the designed alloy, the contents of Cr and Nb are 2.0-2.8 at% and 1-1.3 at% correspondingly, the atomic ratio of Cr to Nb is controlled to be slightly greater than 2:1, and a copper matrix is reinforced by nanophases such as a Cr2Nb phase and a Cr phase. According to the alloy, the high-performance Cu-Cr-Nb alloy with the double-peak grain size and the double-scale nano-phase reinforcing function is prepared through the cooperation of selective laser melting and a special heat treatment process. The tensile strength of the prepared Cu-Cr-Nb alloy at room temperature is larger than 800 MPa, the yield strength of the Cu-Cr-Nb alloy is larger than 710 MPa, the microhardness of the Cu-Cr-Nb alloy is not lower than 256 HV, the elongation of the Cu-Cr-Nb alloy is not lower than 25%, and the conductivity of the Cu-Cr-Nb alloy is not lower than 70% IACS. The tensile strength at 700 DEG C is 145-155 MPa.

The invention discloses narrow-hardenability high-temperature fine grain MnCr gear steel. The narrow-hardenability high-temperature fine grained MnCr gear steel comprises the following components in percentage by weight: 0.19%-0.21% of C, 1.25%-1.35% of Mn, 0.20-0.30% of Si, 1.20%-1.30% of Cr, less than or equal to 0.020% of P, 0.010%-0.025% of S, 0.013%-0.02% of N, 0.034-0.050% of Al, less than or equal to 0.0015% of [O], less than or equal to 0.0002% of [H], and the balance iron and inevitable impurity elements. The invention further discloses a preparation method for the gear steel. The gear steel has the advantages of low cost, high-temperature fine grains, high purity, narrow hardenability, stable performance, and can ensure that the hardenability bandwidth of the steel is narrow, quality of the rolled surface of the steel is good, and the grains are small.

The invention discloses a hard alloy for a cold heading mold and a preparation method thereof. The preparation method comprises the following steps: mixing the following materials in percentage by weight: 22-28% of Co, 70.5-77.5% of WC and the balance of Cr3C2, wherein the Fsss particle size of WC is 1.0-6.0 mu m; and then, performing wet grinding, drying, performing pressure molding, sintering, quenching, and tempering. For a hard phase of the hard alloy prepared by the method disclosed by the invention, the average grain size is 1.2-2.0 mu m, the hardness is 84.0-86.0HRA, the bending strength is above 3100 MPa, and the alpha-Co content is high; the toughness and corrosion resistance of the alloy are favorable; Cr3C2 is almost completely dissolved in the Co phase, thus further strengthening the Co phase and reinforcing the stability of the alpha-Co phase; and transition of alpha-Co to epsilon-Co is inhibited in the use process, thus greatly increasing the comprehensive properties and service life of the hard alloy.

The invention belongs to the field of refractory materials, and particularly relates to a method for synthesizing aluminum-rich spinel through a low-temperature solid-phase reaction. The method specifically comprises the following steps: firstly, mixing 80-90 parts by weight of an aluminum oxide raw material, 10-20 parts by weight of a magnesium oxide raw material, 0.5-2 part by weight of magnesium aluminate spinel micro powder and 0.5-3 part by weight of an additive, and co-grinding the materials until the particle size of the raw materials is in a range of 5-20 microns; transferring the co-ground powder into a high-temperature kiln, heating to 1000-1500 DEG C, and calcining; and finally, keeping for 3-12 hours at the calcining temperature, and implementing naturally cooling or quickly air-cooling to room temperature to obtain the aluminum-rich spinel. A low-temperature synthesis process is adopted, the aluminum-rich spinel synthesized through low-temperature calcination is fine in grain and high in lattice defect degree, and meanwhile the prepared aluminum-rich spinel powder is high in activity. The prepared aluminum-rich spinel does not contain beta aluminum oxide or impurity phases such as free magnesium oxide, and the content of aluminum oxide in the aluminum-rich spinel reaches 80-90%. When the prepared aluminum-rich spinel powder is used in a corundum spinel castable, the aluminum-rich spinel powder has the advantages of high sintering strength and strong slag penetration resistance.

The invention discloses a (2:17)-type SmCoCuFeZrB sintered permanent magnet. The element composition formula of the sintered permanent magnet is Smx(Co1-a-b-c-dFeaCubZrcBd)z, wherein the symbols x, a,b, c, d and z in the formula represent composition ranges of limited elements, and the atomic number ratio of x to a to b to c to d to z is 1:(0.01-0.4):(0-0.03):(0.01-0.05):(0.01-0.04):(6.8-8.4); the magnet has a cellular structure, a cell wall phase is an Sm(CoFeCu)4B phase with a 1:4:1 type crystal structure, and an intracellular main phase is an Sm2(CoFe)17B phase. The invention also discloses a preparation method of the sintered permanent magnet, and the density and orientation degree of the sintered permanent magnet prepared by adoption of the method are incomparable to those of nanocrystalline and amorphous magnets; a heat treatment process, an oxygen control process and the like are matched, uncontrolled decomposition of the phase of the magnet in the heat treatment process is effectively inhibited, effective regulation and control of the microstructure and phase composition are achieved, the adding amount of the Fe element in the sintered (2:17)-type samarium-cobalt magnet isincreased, the intrinsic coercive force of the magnet under the high Fe content is improved, and then the maximum magnetic energy product of the sintered (2:17)-type samarium-cobalt magnet is increased.

The invention discloses a medium-carbon steel large diesel engine output shaft hardening and tempering process. The process comprises the following steps: (1) normalizing: filling an output shaft in a furnace, heating to the temperature of 350 +/-20 DEG C and 600+/-20 DEG C in a staged way, preserving the heat, hanging out the output shaft, blowing cold air to cool the output shaft to room temperature by using a fan; (2) quenching for three times: filling the output shaft into the furnace again, heating to the temperature of 350 +/-20 DEG C, 600+/-20 DEG C and 850+/- 10 DEG C in a staged way; cooling by air and then cooling in a water tank, cooling by the air again and cooling by water again, and then cooling in an oil tank; (3) high-temperature tempering: tempering at the temperature of 565+/- 10 DEG C, preserving the temperature and cooling by the air out of the furnace. By the process, the surface martensite transformation speed at the first stage of a large shaft forging is improved, and the surface quenching hardness of the large shaft forging is improved by adopting the reasonable quenching cooling mode of air cooling-water cooling-air cooling-water cooling-oil cooling. The difference between the inside temperature and the outside temperature of the large shaft forging is reduced by the air cooling adopted by the process, and the cracking tendency of the large shaft forging is effectively reduced.

The invention discloses a heat treatment process for improving the mechanical property of Fe-Mn-Al-C dual-phase steel by utilizing gamma-to-alpha allotropy transformation, and belongs to the technicalfield of automobile steel. The heat treatment process is characterized in that steel is heated to 1273-1373 K after undergoes hot rolling, the temperature is kept for 30 min-1 h, then water cooling is performed to enable to the temperature to reach the room temperature, then cold rolling treatment is performed, the cold deformation amount is 50-80%; the two-phase region temperature is selected for annealing treatment on a cold-rolled steel plate, the annealing temperature is not higher than the heat preservation temperature before cold rolling, and the annealing time is 10 s-5 min; a two-phase structure with transformation of gamma to alpha occurred at the austenite grain boundary is obtained through the heat treatment process, the gamma-phase orientation and the alpha-phase orientation meet the K-S relationship, meanwhile, the solid solution amount of the C in the austenite is increased, and the yield strength and the toughness of the steel are improved; the process is the heat treatment process for improving the strength and plasticity of the dual-phase steel at the same time, and the quality of the Fe-Mn-Al-C double-phase high-aluminum light steel is comprehensively optimized and improved.

The invention relates to the technical field of radioactive waste treatment, in particular to a preparation method of a borosilicate glass ceramic solidified body containing uranpyrochlore. The preparation method comprises the following steps of respectively performing wet mixing drying and pre-sintering, gradual melting, sintering and quenching with SiO2, Al2O3, Na2CO3, B2O3, CaF2, CaO, U3O8 andTiO2 as raw materials to prepare the borosilicate glass ceramic solidified body. The preparation method has the advantages that the crystallization rate of the uranpyrochlore in glass can be regulatedand controlled; the ingredients remained by nuclide in the glass phase can be reduced; the accommodating capacity of nuclide U in the ceramic phase can be improved; the accommodating capacity of thenuclide U in the whole solidified body can be improved; the prepared borosilicate glass ceramic solidified body containing uranpyrochlore has the advantages of uniform crystal grain distribution, hightissue compactness and high intensity.

The invention discloses a novel binding phase hard alloy and a preparation method thereof. The novel binding phase hard alloy is composed of the following components of, in percentage by mass, 10 wt%-15 wt% of cobalt, 10 wt%-15 wt% of nickel, 0.6 wt%-2.5 wt% of silicon carbide and the balance of tungsten carbide. According to the novel binding phase hard alloy, the Si-reinforced Co-Ni binding phase is adopted to reinforce the hard alloy, the ordered reinforcing phase of the hard alloy is dispersed and distributed into the binding phase, under equivalent conditions, compared with an existing Co-Ni binding phase hard alloy, the reinforced hard alloy with Co-Ni-Si as the binding phase has the advantages that the room-temperature and high-temperature bending strength can be improved by 20% or above, and moreover, the process is simple and controllable, and industrialization is facilitated.

The invention provides a critical solid solution and critical repeated cooling aging and annealing heat treatment method which comprises a critical solid solution heat treatment process and a critical repeated cooling aging and annealing heat treatment process. The scheme of the invention has technical feasibility, process adaptability, quality reliability, economic reasonability and use safety, can effectively enhance the advantages and avoid the disadvantages of a conventional mainstream heat treatment method of austenitic stainless steel, fundamentally solves the "one-long one-high four-poor five-low" special heat treatment technical difficult problems of "poor quality stability, low rate of qualified products, low hardness, low mechanical property, poor consistency, poor discoloration and rust corrosion resistance, long heating time, low efficiency, poor heating reliability of heat treatment equipment and low service life and high cost of a high-temperature component" of existing austenitic stainless steel heat treatment, and is particularly suitable for the technical field of heat working engineering such as smelting, steel rolling, forging, heat treatment and the like related to the austenitic stainless steel in steel mills and manufacturers.

The invention provides a critical solid solution and critical multi-cooling variable-temperature aging and annealing heat treatment method. The method comprises a critical solid solution heat treatment process and a critical multi-cooling variable-temperature aging and annealing heat treatment process. The scheme has technical feasibility, process adaptability, quality reliability, economic rationality and use safety, and can effectively enhance the advantages and avoid the disadvantages of a traditional mainstream heat treatment method of austenitic stainless steel, so that the problems that the existing austenitic stainless steel heat treatment is poor in quality stability, low in qualified rate, low in hardness, low in mechanical property, poor in consistency, poor in discoloration and corrosion resistance, long in heating time, low in efficiency, low in cost and the like are fundamentally solved. The critical solid solution and critical multi-cooling variable-temperature aging and annealing heat treatment method is particularly suitable for the technical field of hot working engineering such as smelting, steel rolling, forging and heat treatment related to the austenitic stainless steel in steel mills and manufacturers.