46results about How to "Avoid internal cracks" patented technology

The invention belongs to the field of metallurgical technology, especially relating to steel for a nuclear-island seamless steel tube and a production method thereof. The steel in the invention comprises the following chemical components in percentage by weight: more than 0 and no more than 0.20 percent of C, no less than 0.10 and no more than 0.35 percent of Si, no less than 0.80 and no more than 1.60 percent of Mn, more than 0 and no more than 0.020 percent of P, more than 0 and no more than 0.015 percent of S, more than 0 and no more than 0.25 percent of Cr, more than 0 and no more than 0.50 percent of Ni, more than 0 and no more than 0.18 percent of Cu, more than 0 and no more than 0.10 percent of Mo, more than 0 and no more than 0.06 percent of V, no less than 0.020 and no more than 0.050 percent of Al, more than 0 and no more than 0.030 percent of Sn and the balance of Fe. The steel in the invention has the advantages of meeting the condition that the carbon equivalent is no more than 0.48 (Ceq = C + Mn/6 + (Cr + Mo + V)/5 + [(Ni +Cu)+ 15]<=0.48), controlling the contents of the main elements such as carbon and manganese in the steel, stabilizing the tensile property of the steel tube subjected to simulated destressing heat treatment, and simultaneously ensuring the tensile properties of the tube body and a sample subjected to the simulated destressing heat treatment to meet the technical standards. Because a residual element nickel as an alloy element is added, the low-temperature impact toughness of the steel in the invention is improved, and the impact toughness requirements for the steel at the temperatures of 0 DEG C and minus 20 DEG C are met.

The invention belongs to the field of preparation techniques of oriented silicon steel, and particularly relates to a method for preventing hot rolling edge fractures in oriented silicon steel. The method comprises the step of temperature control in a heating furnace heating and rolling process, including temperature of the oriented silicon steel plate blank before the corner enters the heating furnace, preheating section temperature and first heating section temperature in the heating furnace, and precision rolling inlet temperature and precision rolling finishing temperature. By controlling the corner temperature of the plate blank entering the furnace and the first heating section temperature, the method reduces the thermal stress when heating the corner, and avoids generating internal fractures; and by controlling the precision rolling inlet and finishing temperatures of the continuous rolling mill train and reasonably setting the tension among the machine frames, the method avoids generating the hot rolling edge fractures.

The invention discloses steel for a petroleum casing connecting piece and a manufacturing method thereof, and belongs to the technical field of metallurgy. The steel for the petroleum casing connecting piece comprises the following chemical ingredients in percentage by mass: 0.28 to 0.33 percent of C, 0.20 to 0.35 percent of Si, 0.45 to 0.60 percent of Mn, less than or equal to 0.025 percent of P, less than or equal to 0.025 percent of S, 0.90 to 1.10 percent of Cr, 0.18 to 0.25 percent of Mo, 0.020 to 0.050 percent of alt, less than or equal to 0.25 percent of Cu, less than or equal to 2.0*10<4> percent of H, 40*10<4> to 70*10<4> percent of N, less than or equal to 15*10<4> percent of T.O and the balance of Fe and inevitable impurities. The manufacturing method comprises the following production processes: an initial refining process of an electric furnace, a refining process of a ladle furnace (LF), a vacuum degassing (VD) process, a continuous casting process, a casting blank slow cooling process and an inspection and finishing process. The cleanliness, tissue compactness and uniformity of continuous casting round billets for the petroleum casing connecting piece are improved greatly, and the requirement of the steel for the petroleum casing connecting piece is met.

The invention discloses a bloom continuous casting soft-reduction process used in steel production, and in particular relates to a method for controlling a bloom continuous casting dynamic soft-reduction pressure interval. The pressure interval is determined according to the central solid-phase rate of each casting blank section in the direction of blank drawing; the central solid-phase rate of each casting blank section relative to the upper limit of the pressure interval is less than or equal to the fs, namely Maxopt which is the maximum value of iopt, of each solute element, wherein the fs and iopt are the central solid-phase rates of a casting blank section relative to the minimum Ki of the solute elements; the Ki is the average solute aliquation index of the solute element i in two phase regions when each casting blank section is slightly pressed; furthermore, the central solid-phase rate of each casting blank section relative to the lower limit of the pressure interval is more than or equal to the fs, namely Minopt which is the minimum value of iopt, of each solute element. The pressure interval determined by the method can effectively improve central aliquation and also reduce cavity, looseness and crack; and the pressure interval has stable use effect and is suitable for bloom continuous casting production.

The invention discloses a manufacturing method of a TA6 titanium alloy large-width thin plate. The manufacturing method includes: 1, manufacturing a composite plate; 2, performing first heating; 3, subjecting the composite plate to first fire rolling to obtain a first semi-finished plate; 4, performing second heating; 5, subjecting the first semi-finished plate to second fire rolling to obtain a second semi-finished plate; 6, grinding before third heating; 7, subjecting the second semi-finished plate to third rolling to obtain a third semi-finished plate; 8, annealing the third semi-finished plate; 9, subjecting the third semi-finished plate to temperature rolling to obtain the TA6 titanium alloy large-width thin plate of 2-4mm in thickness and 1200-1500mm in width. By the manufacturing method, internal defects during processing of the TA6 titanium alloy large-width thin plate can be reduced effectively, and the TA6 titanium alloy large-width thin plate is high in stability, excellent in mechanical performance and high in yield. The manufacturing method is simple and easy in realizing of industrialized production.

The invention relates to a special pressed carbon block for blast-furnace ironmaking as well as manufacturing and using methods thereof, belonging to the technical field of pressed carbon block products capable of partially or totally replacing cokes in the blast-furnace ironmaking process as well as the manufacturing and using methods thereof. The pressed carbon block is characterized by being obtained with coal as a basic raw material through pressing and dry distilling and solidifying processing, and having the apparent density not less than 980 kg/m<3> and the granularity not less than 15mm and not more than 290 mm. The manufacturing method of the pressed carbon block comprises the following steps of: blending coal; grinding; mixing; cooling, and the like. The manufacturing method ofthe pressed carbon block is characterized by also comprising the following steps of: pressing; dryly distilling; and solidifying. In the coal blending step, coal needs to be ensured to contain a proper amount of viscous components after coal blending; and in the grinding step, the granularity of coal powder is required to be controlled within a range of 0-1.2 mm. In the using method of the pressed carbon block, not less than 3 percent of the cokes are replaced by utilizing the special pressed carbon block for the blast-furnace ironmaking.

The invention discloses a physical experiment and numerical simulation combined method for predicting metal extrusion forming cracking. The method comprises the steps that first, a hot-stretch test isperformed on metal, and then a Normalized Cockcroft&Latham damage model is selected for calculation to obtain a critical damage value of the metal; second, simulated verification is performed on thecritical damage value of the metal; and third, the critical damage value of the metal after simulated verification is embedded into a metal extrusion finite element model, and the cracking phenomenonin the metal extrusion forming process is predicted. According to the method, a physical experiment and simulated verification are combined to acquire the reliable critical damage value of the metal,then the positions and shapes of metal surface and internal cracks generated in multiple extrusion forming processes are predicted through numerical simulation of the extrusion processes, an error caused by a test mistake is avoided, prediction precision is improved, the prediction range is expanded, therefore, crack generation is avoided, and the quality of metal extrusion pieces is improved.

The invention provides corrosion-resistant steel for an oil well and relates to the technical field of steel. The corrosion-resistant steel is prepared from, by mass, 0.10%-0.20% of C, 0.20%-1% of Si, 0.05%-1.5% of Mn, 4.0%-6.0% of Cr, 0.10-1.0% of Ni, 0.10%-0.8% of Mo, 0.20%-0.80% of Cu, 0.01%-0.10% of Al and the balance Fe and inevitable impurity elements, wherein the total content of the inevitable impurity elements is not higher than 0.5%. The corrosion-resistant steel for the oil well achieves the mechanical properties that the yield strength ranges from 1,020 MPa to 1,150 MPa, the tensile strength ranges from 1,140 MPa to 1,300 MPa, the elongation is around 20%, and the Kv of a 140 ksi steel grade casting pipe product is around 30 J at 0 DEG C. In addition, the corrosion-resistant steel for the oil well belongs to the category of low-alloy steel, and the content of Cr and Ni is low; and the CO2 corrosion resisting performance and the H2S corrosion resisting performance of the steel are improved through the methods such as simultaneously adding a small quantity of elements retarding the anode process and elements promoting the cathode process and the surface activity. The corrosion-resistant steel for the oil well is low manufacturing cost and high in CO2 corrosion and H2S stress corrosion resistance.

A multilayer capacitor and a board having the same includes external electrodes and internal electrodes. The external electrodes include connection portions formed on a mounting surface of a capacitor body and band portions formed on side surfaces of the capacitor body, and the internal electrodes include body portions overlapping each other and lead portions extended from the body portions to the mounting surface of the capacitor body, to thereby be connected to the connection portions of the external electrodes. The body portions are formed to be spaced apart from virtual lines connecting distal ends of the connection portions and distal ends of the band portions to each other.

The invention relates to a core cementing mold for sand consolidation formula performance evaluation and an experimental method of the core cementing mold. The core cementing mold for sand consolidation formula performance evaluation is prepared through the method that a 3D structure chart of the core cementing mold is drawn, wherein the shape of the mold is an annular cylinder, the annular cylinder is composed of an inner cylinder body and an outer cylinder body in a coaxial mode, fixing bands connected with the inner cylinder body and the outer cylinder body are arranged in an annular space,the two ends of the inner cylinder body are open, the upper end of the annular space is open, and the bottom end of the annular space is closed; the 3D structure chart is imported into a 3D printer,and the core cementing mold is printed through a polylactide material; and the annular space of the printed core cementing mold is filled with dried sand grains to simulate a sand bath environment, the lower end opening of the inner cylinder body is connected with a rubber plug with holes, waterproof glue is smeared at the connecting position, and a layer of screen is attached to the outer portionof the rubber plug with the holes. According to the core cementing mold, the annular space is filled with the sand grains to simulate the sand bath environment, and meanwhile an intact cemented corecan be taken out just by cutting the soft outer wall of the mold through a knife after core cementing is over, so that damage to the cemented core is avoided.

Disclosed herein is a semiconductor package substrate including a base substrate, a mounting member mounted on an upper portion of the base substrate, and an adhesive layer formed between the base substrate and the mounting member, wherein the adhesive layer includes a thermally conductive adhesive and a ductile adhesive formed at the outer circumference of the thermally conductive adhesive.

The invention discloses a technical method for improving the quality of high-strength cable steel casting blanks. The technical method comprises the steps that (1) the casting blanks enter a pit at the temperature of 550-680 DEG C to be slowly cooled, the blanks are stacked like a Chinese character 'jing', the blanks are subjected to capping cooling firstly at the cooling speed of 6-8 DEG C/h, andafter the temperature reaches 300 DEG C, the casting blanks are subjected to uncapping cooling to 200 DEG C or below and then taken out of the pit; (2) cogging is conducted, specifically, the castingblanks are heated and then rolled, and the initial rolling temperature is larger than or equal to 1100 DEG C; (3) shot blasting flaw detection is carried out, specifically, the shot diameter is 0.5-1.0 mm, and the shot blasting advancing speed of the casting blanks is 0.2-0.3 m/s; and (4) local coping is conducted, specifically, the coping modes include mechanical point coping and chamfer coping.According to the technical method, for the high-strength cable steel casting blanks, the temperature of pit entry for slow cooling and the cooling speed are controlled, and thus generation of abnormal structures, surface cracks and internal cracks of the casting blanks is effectively avoided; and by adoption of mechanical point coping and chamfer coping, the yield and the production efficiency are improved, and the comprehensive benefit is remarkable.

The invention discloses a method used for medium and low temperature mold dismantling of a large-scale extra-thick plant blank. The method comprises the following steps of: pouring molten steel into a large-scale extra-thick plate blank mould cavity; carrying out air-blowing or spray cooling for a large-scale extra-thick plate blank metal mould to enable the large-scale extra-thick plate blank to be solidified completely; carrying out the medium and low temperature mold dismantling; and keeping the temperature of the large-scale extra-thick plate blank and cooling the plate blank slowly. The method used for the medium and low temperature mold dismantling of the large-scale extra-thick plant blank, disclosed by the invention, removes shrinkage cavities and unconsolidated defects inside the large-scale extra-thick plate blank and hot cracks on the outer surface of the large-scale extra-thick plate blank.