40results about How to "Avoid white spots" patented technology

The invention belongs to the technical field of large forging heat treatment processes, and mainly relates to a post-forging heat treatment process for 45Cr4NiMoV alloy steel large back-up rolls of rolling mills. A forged back-up roll is cooled to 400 DEG C to 500 DEG C by the air and put into a furnace, and the material temperature in the heat treatment furnace is not lower than 600 DEG C; a high-temperature normalizing plus low-temperature normalizing plus spheroidizing annealing plus high-temperature tempering process is adopted, and air cooling is carried out. The adopted post-forging heat treatment process disclosed by the invention is characterized in that: crystalline grains are thinned; the structure is regulated, so that the network structure is removed; the carbon segregation ofthe upper part of the large steel ingot is considerable, temperature higher than Ac1 is kept for a long time, consequently, part of carbide is remelted, the remaining unmelted carbide is spheroidized, and a granular pearlite structure is obtained during cooling; consequently, the structure toughness is high, and structure preparation is done for the next step of heat treatment; and fish eyes are prevented.

The invention discloses a post-forging thermal treatment method for a heavy forging of a hot-wall hydrogenation reactor. The method is used for performing post-forging thermal treatment on the heavy forging, which is made of 12Cr2Mo1 and is 1,500-4,500 millimeters in outer diameter and 100-300 millimeters in wall thickness, of the hot-wall hydrogenation reactor. The post-forging thermal treatment method is characterized by comprising the following steps: I, controlling the final forging temperature, performing air cooling until the surface temperature of a forging is 250-350 DEG C, and feeding the forging into a heating furnace; II, raising the temperature of the heating furnace to 600-700 DEG C at a speed of less than or equal to 80 DEG C per hour, and preserving heat; III, raising the temperature of the heating furnace to 880-930 DEG C at the maximum power of the heating furnace, and preserving heat; IV, discharging a workpiece, and cooling the workpiece in water until the surface temperature of the workpiece is lower than or equal to 80 DEG C; V, feeding the workpiece into the heating furnace for later use, raising the cavity temperature of the heating furnace to 650-720 DEG C at a speed of less than or equal to 80 DEG C per hour, preserving heat, discharging and performing air cooling. By adopting the post-forging thermal treatment method, the performance is preserved in a post-forging thermal treatment process while the quality of the forging is ensured, the production period of the forging of the hot-wall hydrogenation reactor is effectively shortened, and the cost is reduced.

The invention aims to provide a forging process for a GCr15 roller sleeve. The forging process comprises the steps that firstly, a forge piece is heated; secondly, the roller sleeve is subjected to four-time heating forming forging, specifically, four-time heating forming is adopted as the forging technique of forging of the GCr15 roller sleeve, namely ejection and upsetting, punching, drawing-out and round rolling reshaping; and thirdly, annealing and cooling are conducted. The machining process is improved, so that the length of drawing-out and punching during forging is prolonged, straightening of the forge piece during punching forging is improved, the uniformity of the wall thickness is improved, white dots in the sleeve are prevented, and the performance of the forge piece is improved.

The invention discloses a preparation method for texture structure of crystalline silicon solar cell, comprising the following steps: 1) placing a silicon wafer into an alkaline solution and removing the damage layer on the silicon wafer surface; 2) placing the silicon wafer in an acidic solution and reducing the structural differences between the different crystal grains; 3) forming a porous layer structure on the surface of the silicon wafer obtained from step 2; and 4) conducting surface etching with a first chemical etching solution for the texture structure of crystalline silicon solar cell. According to the method of the invention, the surface of the silicon wafer undergoes a pretreatment first, that is, the removal of the damage layer in alkali solution, and then proceeds to the homogeneous corrosion in the acid solution. The cooperated use of the two finally forms the surface structure suitable for preparing the nanometer texture, which is obviously advantageous in terms of photoelectric conversion efficiency.

The invention relates to a flocking process and production equipment, in particular to a yarn flocking flow process and continuous production equipment. The yarn flocking flow process includes the steps of feeding, pretreatment, gluing, flocking, drying, brushing and winding, and adding a yarn rotating device to make the circumferential surface of the yarn adhere evenly and densely. In the process, the hairiness on the surface of the substrate is cleaned by the decontamination solution, which facilitates the uniform spraying of the adhesive in the subsequent process and prevents white spots on the flocking products; the products prepared by using the yarn flocking process and production equipment have stable performance and relatively high High use value.

Disclosed is a sulfureted hydrogen-proof stress corrosion high pressure-resistant forge piece, comprising the compositions, in weight percent: C: 0.26 to 0.30, Mn: 0.80 to 1.00, Cr: 0.80 to 1.00, Si:0.20 to 0.35, Ni: 0.50 to 0.95, Mo: 0.20 to 0.30, P<=0.012, S<=0.010, Cu<=0.20, H<=2ppm, O<=50ppm, N<=85ppm, balance Fe; and a manufacturing method comprises the following steps of: secondary refiningand smelting by an electric furnace, and casting for forming ingot; heating and forging, with a heating speed of 100 to 150DEG C / h to rise the temperature to 1190 to 1230DEG C, and then preserving the heat for over 8 hours; forging steel ingot to have the size of a finished product; forging temperature range: 800DEG C to 1130 DEG C; adopting an upsetting drawing process, with a forging ratio >=6;and air cooling to reach a temperature of between 420 and 470DEG C after the forging and preserving the heat for over 2 hours, normalizing, with a temperature of between 870 and 890DEG C, and annealing, with a temperature of between 670 and 690DEG C. The indexes such as yielding, tensile strength, grain size and non-metallic inclusion of the forge piece meet the designed 105MPa pressure demand, and the forge piece is corrosion resistant.

The invention provides a COMS image sensor and a manufacturing method thereof. When N-type or P-type source-drain injection is carried out on a logic region, a first photoresist firstly coats a semiconductor substrate; a source-drain region which needs to be subjected to source-drain injection is exposed through exposure and development; and a partial-thickness dielectric layer is etched and N-type or P-type source-drain injection is carried out. The dielectric layer in a protective pixel region of the first photoresist is not etched, and the dielectric layer prevents ion injection from damaging the semiconductor substrate on the surface of a photosensitive diode when the ion injection is carried out in a photosensitive diode region in the pixel region, so that white dots, caused by a semiconductor damage, of the COMS image sensor are avoided; the quality of the COMS image sensor is improved; the method is simple and convenient to operate; and the performance of the COMS image sensor is not affected.