10results about How to "Avoid crack defects" patented technology

The application discloses an inorganic copolymer anticorrosive paint and a preparation method thereof, and relates to the technical field of paints. The inorganic copolymer anticorrosive paint comprises the following raw materials in parts by weight: 20-30 parts of silica sol, 8-15 parts of sodium hydroxide, 30-45 parts of metakaolin, 8-20 parts of quartz sand, 15-25 parts of water, 0.3-2 parts of sodium polyacrylate, 0.2-3 parts of polydimethylsiloxane emulsion, 5-12 parts of modified nanometer titanium dioxide, 6-10 parts of modified epoxy resin, 10-25 parts of hydroxyethyl methacrylate, 5-10 parts of zinc phosphate, 3-8 parts of aluminum tripolyphosphate and 2-6 parts of red iron oxide. The inorganic copolymer anticorrosive paint has scientific raw material proportioning, and the anticorrosive performance is enhanced through the modified nanometer titanium dioxide and the epoxy resin. In the preparation, step-by-step feeding and ultrasonic dispersion are adopted to ensure that the materials are uniform, and vacuum degassing and nitrogen protection are adopted to improve the stability. The silica sol, the zinc phosphate and other components have a synergistic effect, a dense coating is formed, the anticorrosive performance is high, the construction performance is good, and the inorganic copolymer anticorrosive paint is suitable for various scenes.

The invention discloses a plate pre-drawing and dieless mirror image loading composite forming process and a product, and belongs to the technical field of metal component forming and manufacturing. The method is used for solving the problems of cracking, ultra-poor thinning, low dimensional precision and the like in the forming process of the high-strength aluminum alloy thin-wall component with local continuous large-area bulge and local large wall angle characteristics in the aerospace field. According to the method, through two-stage area expansion distribution, the thinning amount of each stage is effectively controlled, and the cracking problem caused by one-time large deformation in a single process is avoided. And mirror images are cooperatively loaded on the local part of the plate to form a three-dimensional stress state, so that the forming limit is improved. And in-mold constraint aging synchronously realizes strengthening and shape righting, and is obviously superior to the traditional process.

This invention discloses a method for processing a self-locking nut for a titanium alloy pallet, belonging to the technical field of titanium alloy pallet nuts. The method includes: Step 100, blanking; Step 200, hot upsetting one end of the bar stock multiple times to obtain a pallet disc, yielding semi-finished product A; Step 300, solution heat treatment of semi-finished product A; Step 400, tapping threads on the inner wall of the threaded bottom hole using a spiral flute tap, yielding semi-finished product B; Step 500, machining the outer shape of the nut body section; Step 600, stamping the pallet disc to form two pallets, yielding semi-finished product D; Step 700, machining a closing groove, yielding semi-finished product E; Step 800, aging treatment of semi-finished product E; Step 900, surface treatment of semi-finished product E, yielding the finished product. Multiple hot upsetting of one end of the bar stock effectively avoids folding and cracking defects in the blank. Using a spiral flute tap ensures that the thread processing quality and surface finish meet quality requirements.

A housing includes a shell, three sheet metal parts, a long rib, a short rib, and two sheet metal parts. The shell contains annularly distributed inner support blocks. An upper flange is located at the top of the shell, a lower flange at the bottom, and a middle flange is located between the upper and lower flanges on the inner wall of the shell. Two sheet metal parts are located between the lower flange and the side wall of the shell. The sides of the two sheet metal parts are connected to the side of the middle flange by an arc-shaped connecting plate. An upper horizontal circumferential seam exists at the connection between the connecting plate and the middle flange, and a lower horizontal circumferential seam exists at the connection between the connecting plate and the two sheet metal parts. Gaps exist at both the upper and lower ends of the side wall of the shell, filled with insulating cotton sealing plates. A layer of insulating cotton is also provided on the inner wall of the shell. This design reduces the depth of the arc crater, effectively avoiding arc crater crack defects, simplifies the manufacturing of structural components, and significantly improves the welding quality of the wall panels and the housing.

The invention discloses a heat treatment method for reducing quenching and tempering state surface hardness of 15CrMoR, and belongs to the technical field of metallurgy. The heat treatment method comprises quenching and tempering heat treatment. In the quenching process, the heating temperature ranges from 830 DEG C to 840 DEG C, the total heating time ranges from 2.0 min / mm to 2.5 min / mm, and water cooling is conducted to the room temperature after discharging; and in the tempering process, the heating temperature is 720-730 DEG C, the heat preservation coefficient is 3-3.5 min / mm, and air cooling is conducted after discharging. The structure of the tempered steel plate is a two-phase structure of ferrite and tempered martensite. The produced steel plate has good obdurability matching, the surface hardness is smaller than or equal to 220 HB, and the crack defect in the machining process of rolling, welding and the like is avoided.

The invention discloses a zinc alloy and a hot extrusion forming process thereof, and belongs to the technical field of zinc alloy processing. The process comprises the steps of blank pretreatment, segmented temperature control heating, segmented temperature control extrusion and double-stage aging treatment. The zinc alloy comprises the following components in parts by weight: 30-60 parts of aluminum, 0.5-2 parts of magnesium, 5-15 parts of copper, 0.1-0.3 part of rare earth, 0.05-0.15 part of zirconium and the balance of zinc. Through pretreatment combination of mechanical grinding, ultrasonic cleaning and phosphating treatment, a composite protection heating atmosphere of inert gas and trace hydrogen, segmented extrusion control of mold temperature and extrusion speed cooperation and double-stage aging treatment, the strength and toughness of the alloy are cooperatively improved. The tensile strength of the product is 350-420 MPa, the elongation is 12-18%, and the product is excellent in corrosion resistance, high in process stability and suitable for the field of high-end equipment manufacturing.

The application discloses a forming die and forming method of a composite material component with a gradually-changing cross-section feature, and belongs to the technical field of composite material component manufacturing. The forming die mainly comprises an upper die, a bottom die, a core block and a middle frame edge strip, wherein the core block comprises a central core block and a plurality of occupying core blocks, and the middle frame edge strip comprises four independent edge strips. When the pre-impregnated material is laid in the forming die, the occupying core blocks are used for occupying, the middle frame edge strip is used for fastening, and pre-compaction operation is performed in combination with a pre-compaction tool and an occupying tool, so that the composite material component with the gradually-changing cross-section feature can be formed. The application can reduce the product extrusion caused by the cooling shrinkage of the mold steel material caused by the thermal expansion factor, the resin enrichment caused by the mold extrusion fluctuation of the thin-thick feature structure area, improve the heat transfer efficiency, control the resin viscosity, and effectively improve the product forming quality.

The present application relates to polyvinyl chloride pipe manufacturing technology field, disclose a kind of modified PVC power cable protection pipe, including polyvinyl chloride resin, heat stabilizer, pentaerythritol, stearic acid, calcium carbonate, polyolefin alloy ionomer masterbatch and liquid complexing agent.Polyolefin alloy ionomer masterbatch is composed of octene-1 and ethylene copolymer, high-density polyethylene, maleic anhydride grafted polyolefin elastomer and active zinc oxide.Liquid complexing agent is composed of isopropyl tri (dioctyl pyrophosphoric acyloxy) titanate and epoxy soybean oil.Polyvinyl chloride dry mix and polyolefin alloy ionomer masterbatch are melt extruded when preparing, and liquid complexing agent is injected laterally.The present application forms toughening phase by polyolefin alloy ionomer masterbatch to absorb and disperse impact stress, and liquid complexing agent improves compatibility of formula raw materials.Lateral injection process promotes liquid complexing agent to directly act on mixed interface, and improves the compactness of modified PVC power cable protection pipe.

The utility model relates to the technical field of silencers, and discloses a silencer assembly which comprises a cylinder body, stamping end covers are fixed at two ends of the cylinder body, pressing grooves are arranged on outer side surfaces of the stamping end covers in an array mode, connecting sleeves are fixed on the stamping end covers, silencing hole pipes are fixed in the connecting sleeves, red copper transition terminals are fixed at one ends of the silencing hole pipes, and the red copper transition terminals are fixed at the other ends of the silencing hole pipes. Silencing holes are formed in the silencing hole pipe in an array mode, and the stamping end cover is connected with the cylinder body in a welded mode. After the silencer assembly and the cylinder body are integrally formed, the stamping end covers which are independently formed are arranged at the two ends of the cylinder body, cold hardening in the material spinning process is reduced, the material cracking defect is avoided, the silencer avoids repeated spinning and rolling, the production cost is reduced, the machining efficiency is improved, the combination modes of the two ends of the cylinder body are diversified, and the practicability is high. The silencer assembly is suitable for various silencer structures, the stamping end cover is independently connected with the silencing hole pipe and the barrel in a welded mode, operation is easy, the production difficulty is lowered, and the service life of the silencer assembly is prolonged.

The invention discloses a method for producing H08A semi-killed low-silicon welding rod steel by adopting a small square billet process, and belongs to the technical field of ferrous metallurgy. The method comprises the four procedures of converter smelting, LF refining, continuous casting and rolling, by optimizing the technological parameters of all the procedures, precise control over the silicon content and effective removal of inclusions are achieved, and the product quality stability is improved; the sulfur content and the phosphorus content are both smaller than or equal to 0.030%, the inclusion rating is smaller than or equal to 1.5 grade, and the purity of the welding rod steel is improved; the silicon mass fraction is stabilized at 0.03-0.07%, and the problem that the welding performance is poor due to the fact that the silicon content in a traditional process exceeds the standard is solved.