69results about How to "No welding defects" patented technology

The invention discloses a technology for repairing surfacing of a piston rod of a super large marine diesel engine, and the technology can carry out the deep repair of the surface of the piston rod. The adopted surfacing process is as follows: flaw detection and straightening are carried out on the piston rod, turning machining is carried out on the surface of the piston rod to remove a defect layer, and individual deeper cracks are manually removed by grinding; fire whirl is used for heating the piston rod twice, the first heating is carried out till 200 DEG C-250 DEG C, the heating is stopped, the race rotation is carried out for 30 minutes, the second heating is further carried out after the temperature difference between the interior and the exterior is reduced, and a surfacing machine tool is rotated after reaching 250 DEG C-300 DEG C; submerged arc welding is used for rotating dual heads of the surfacing machine tool and a 2Cr13 flux-cored welding wire for carrying out the simultaneous surfacing, and asbestos cloth is used for wrapping and keeping the temperature during the welding process; the piston rod wrapped by the asbestos cloth for slow cooling after the surfacing achieves the size requirement, when the temperature is decreased to be lower than 100 DEG C, the piston rod wrapped by the asbestos cloth is vertically placed till the temperature is decreased to the room temperature, and then the temperature-keeping cloth is removed. The surface of the piston rod after the repair by employing the method has no weld defects, the piston rod fully meets the performance requirements, and the cost is only about one fifth of the cost for fabricating a new piston rod.

The invention discloses a method for welding a thick aluminum alloy plate. The method comprises a cleaning process, a preheating process and a welding process, wherein the cleaning process is carried out in a chemical cleaning way and comprises steps of: dipping a part to be welded in a 8-10% NaOH solution for more than 10 minutes, and then dipping in a 40-50% HNO3 solution for 30 seconds to 1 minute, wherein sensing heating equipment is adopted in the preheating process, and the preheating is carried out at 230 to 250 DEG C; joints in the welding process are in form of angle joint, and the non-melting electrode tungsten electrode gas shielded welding is carried out in the welding method, the welding parameter can be shown as that the current is 250 to 290A, the current polarity is performed by alternating current, Ar with purity not less than 99.99% is adopted as the protective gas, and the gas flow is at 7-13 liters per minute. Through the method, little welding deformation is generated, the correcting is easily carried out after welding, the product quality can be improved, the production efficiency can be increased, and the manufacturing cost can be greatly reduced.

The invention discloses a flux-cored wire and a method for welding a cold-rolled back-up roll by the same, and relates to the welding technology. By using a steel strip as a sheath, the flux-cored wire comprises the following components in percentage by mass: 0.15 to 0.50 percent of carbon, 0.10 to 1.00 percent of silicon, 0.30 to 2.00 percent of manganese, 3.50 to 7.00 percent of chromium, 0.50 to 2.50 percent of molybdenum, 1.00 to 3.50 percent of tungsten, 0.20 to 1.00 percent of vanadium, 0.20 to 3.00 percent of nickel, 0 to 0.03 percent of sulfur, 0 to 0.03 percent of phosphorus, and the balance of iron. The flux-cored wire needs to maintain the surfacing interpass temperature of the cold-rolled back-up roll between 300 and 350 DEG C during constant temperature surfacing work. The flux-cored wire well solves the problem that the intensity of a surfacing material is not matched with the toughness after surfacing of the cold-rolled work roll, so that the hot-rolled back-up roll has high intensity and excellent toughness. Therefore, the service life of the cold-rolled back-up roll is improved.

It relates to a pile-up welding composite straightener roll and the preparation technique, belonging to the art of mechanical device, and it especially relates to a straighter roll for a plate hot straightening machine. The straightener roll uses alloy constructional steel 42CrMo wrought-steel as the base metal to prepare mandrel of roll body, and is built-up an operational layer of 5-15mm by thicken on the surface of the roll body, the chemical composition of the deposited material of the operational layer being: C:0.36-0.45%, Cr: 12.00-14.00%, Ni:2.00-2.50%, Mo: 2.00- 3.00%, W: 2.00- 3.00%, Ti: 0.85-1.25%, Si: <=1.50%, Mn: <= 2.00%, P<= 0.035%, and S: <=0.03%. In the technique it uses 1250 type automatic buried arc building-up device, applies bobbing building-up to build up the operation layer of roll body, and uses the 260 weld flux as the welding material. The straightener roll has a long work life and a high strength of roll body, and it can be repaired and reproduced a plural of times.

The invention discloses a flux-cored wire and a method for welding a hot-rolled back-up roll by the same, and relates to the welding technology. By using an iron-based steel strip as a sheath, the flux-cored wire comprises the following components in percentage by mass: 0.15 to 0.60 percent of carbon, 0.10 to 2.00 percent of silicon, 0.15 to 2.00 percent of manganese, 2.50 to 7.00 percent of chromium, 0.50 to 2.50 percent of molybdenum, 0.30 to 3.50 percent of tungsten, 0.20 to 1.00 percent of vanadium, 0.20 to 3.00 percent of nickel, 0 to 0.03 percent of sulfur, 0 to 0.03 percent of phosphorus, and the balance of iron. The flux-cored wire needs to keep the surfacing interpass temperature of the cold-rolled back-up roll between 300 and 350 DEG C during constant temperature surfacing work. The flux-cored wire well solves the problem that the intensity of a surfacing material is not matched with the toughness after surfacing of the cold-rolled work roll, so that the hot-rolled back-up roll has high intensity and excellent toughness. Therefore, the service life of the hot-rolled back-up roll is improved.

The invention provides a nano particle reinforced Ag-base composite brazing filler metal and a preparation method thereof and relates to a composite brazing filler metal and a preparation method thereof. The nano particle reinforced Ag-base composite brazing filler metal can be used for solving the technical problems that a joint obtained by a soldering ceramic and metal by utilizing a common Ag-base brazing filler metal is low in service temperature and poor in performance under a high temperature environment. The brazing filler metal provided by the invention is prepared from Ag powder, Cu powder, Ti powder and nano Si3N4 particles. The method comprises the following steps of 1, preparing materials; and 2, performing ball milling, so as to obtain the nano particle reinforced Ag-base composite brazing filler metal. The shearing strength of a joint obtained by soldering Si3N4 ceramic and TiAl alloy by utilizing the composite brazing filler metal provided by the invention at a high temperature of 400 DEG C is up to 156MPa, and is three times that of the joint obtained through soldering by utilizing a commercial AgCuTi brazing filler metal, and the shearing strength of the joint at room temperature is up to 115MPa.

The invention discloses the application of laser welding on Unimach and a welding method thereof, which comprises the steps of cutting a Unimach welded sample cut by adopting a molybdenum wire; polishing the welding joint of the sample with metallographical sand paper before welding; removing rust and chips; cleaning with acetone; and adopting a CO2 laser for laser welding. Compared with prior art, the method adopts the laser for welding the Unimach without the need of gas shielding, and penetration welding with welding thickness of 1mm results in good welding effect. The welding joint is smooth and fine macroscopically, without cracks or holes generated. The microstructure analysis and the stretching fracture analysis show that the welding joint is free of welding defects, impurities and pores, and has good fusion, thus greatly improving the anti-cracking performance of the Unimach welding joint.

The invention provides a laser welding method. According to the method, a laser welding machine and a circuit board to be welded are provided, a plurality of bonding pads to be welded are arranged on the circuit board, the laser welding machine comprises a focusing head and a tin feeding head, the tin feeding head comprises a tin feeding end, the tin feeding end can feed a tin wire continuously, the tin feeding head is located between the focusing head and the bonding pads, before high-power light of the focusing head exits or while high-power light exits, a section of the tin wire is fed by the tin feeding head, and the tin wire, the focusing head and the bonding pads are located on the same straight line. According to the laser welding method, the welding speed is high, the welding precision is high, the requirement for control equipment is not high, the production cost is low, stability is improved greatly, and the laser welding method has high market value.

The invention discloses an automatic five-wire submerged arc welding method for thick-wall welded pipes. The automatic five-wire submerged arc welding method uses five welding wires. The welding inclination angles of the five welding wires along the travelling directions of the welded pipes are arranged from forward inclination to backward inclination sequentially. Therefore, the root of a welding pass of a weldment can be welded thoroughly, welding forming is achieved at one time, excess welding defects can be avoided, productivity is high, heat affected zone is small, and welding metal structure is uniform. The automatic five-wire submerged arc welding method for the thick-wall welded pipes can be widely applied to mass longitudinally submerged arc welding of steel pipes.

The invention discloses a high-heat-input double-wire submerged-arc efficient welding method. The high-heat-input double-wire submerged-arc efficient welding method includes technological steps of S1,adopting X-shaped grooves; S2, adopting special high-heat-input submerged-arc sintered welding flux and baking the special high-heat-input submerged-arc sintered welding flux; S3, carrying out preheating until the temperatures reach 100-150 DEG C and the interlayer temperatures reach 100-200 DEG C; S4, welding front surfaces under the condition of backing heat input lower than 80 KJ/cm and carrying out filling and cover surface welding under the condition of heat input of 80-120 KJ/cm; S5, directly thoroughly welding reverse surfaces by the aid of high currents without gouging under the condition of heat input of 100-150 KJ/cm; S6, carrying out post-weld slow cooling. The high-heat-input double-wire submerged-arc efficient welding method has the advantages that the high-heat-input double-wire submerged-arc efficient welding method with the high heat input of 80-150 KJ/cm is high in welding efficiency and little in welding deformation, weld seams are free of defects, and welded connectors are excellent in mechanical performance; particularly, the welded connectors are good in low-temperature impact toughness, and low-temperature impact energy of the welded connectors at the temperatures of -40 DEG C is higher than 100 J.

The invention discloses a rosin derivate for soldering flux and a preparation method. The molecular structural formula of the rosin derivate for soldering flux sees the specification, wherein n is 3 or 4. The rosin derivate for soldering flux has a good solubleness with a solvent, and is free of crystallizing, high in film-forming property, outstanding in heat stability, high in performance for wetting lead-free solder, and high in soldering flux activity; when in use, a halogen activator is not needed to be added; the thermal stability is high, and degrading and carbonizing at high temperature can be avoided; the mobility and heat conductivity at high temperature are high; the formed welding points are regular and free of bubble, concave pits and other poor welding phenomena; in addition, the corrosion after welding is small; the preparation cost is low, and no pollution is generated.

The invention relates to the field offriction welding, and provides a friction welding heating method by using laser. Particularly, before welding, end faces of work piecesare radiated by the laser, so as to make the surface layer in ahigh temperature or micro melting state, then friction and upsetting process are conducted swiftly, so as to extrude liquid metals and parts of thermoplastic metals, finally the connection is formed through diffusion and recrystallization. According to the method, the unique advantages of highdensity of laser energy, precise and controllable airspace and time domain, and the characteristics of good quality of friction welding joint and high production efficiency and the like are synthetically utilized. The method has the advantages that external input energy is used as a main energy source; the required pressure and torque of friction welding are greatly decreased; the requirementfora welding equipment is reduced; processing ranges of traditional friction welding are expanded: the heterogenetic materials with big difference in physical and chemical characteristics, workpieces with small stiffness, thin walls and minor diameters, and workpieces with low friction coefficient, with-surface layer, high temperature and strength are welded.

The invention discloses a solid flux for automatic soldering of soldering tin, prepared from the following components by weight percent: 80-86% of deionized water, 4.5-10% of co-solvents, 4-7% of active agents, 0.4-1.2% of nonionic surfactants, 0.9-1.4% of film-forming agents and 0.2-0.4% of corrosion inhibitors. The active agents are prepared from the following components: 0.3-0.7% of 2-hydroxypropanoic acid, 0.7-1.3% of 1,2-ethane dicarboxylic acid, 0.4-0.8% of 1,3-acetone dicarboxylic acid, 0.6-1% of undecanedioic acid, 0.5-0.8% of malonic acid, 1-1.8% of polyethylene glycol PEG-200 and 0.5-1% of succinimide. Compared with the prior art, the solid flux is a water-based flux used for solving problems of no continuous soldering or pinholes of tin soldering of precision circuit boards, has the advantages of good soldering firmness, environmental protection performance and safety, high activity, excellent wettability, low corrosion and low cost, is simple and convenient to prepare, can be operated at room temperature, has low requirements for equipment and has a good application prospect.

The invention discloses a welding method for increasing the surface hardness of a capping bead of a wear resistant steel plate. A high-strength wear resistant steel plate of which the hardness grade is HB360 to HB450 is adopted, the thickness of the high-strength wear resistant steel plate is 16 to 80 mm, a welding wire ER69-G of which the tensile strength Rm is greater than or equal to 690 MPa and argon-rich mixed gas shielded welding are adopted to perform backing welding and filling welding on the interior of a weld groove of a wear resistant steel member, when the capping bead is welded, awear resistant alloy wire is added into the groove, then the capping bead is welded, the fusion of a welded joint is good, and no welding defect exists in the welding seam junction of a capping layerand a packing layer. The welding wire does not need to be replaced in a welding process, only the wear resistant alloy wire is added when a welding seam of the capping layer is welded, and the manufacturing process is relatively simple. According to the process measure, the welded joint of the wear resistant steel member has good comprehensive mechanical properties, and the wear resistant alloy wire is added to the capping bead, so that the hardness of the capping bead reaches more than HRC35, the surface weld metal has high wear resistance, the wear resistant steel member is prevented from failing due to the wear of the welding seam, and the service life of the product is prolonged.

The invention belongs to the technical field of solder, and particularly relates to a lead-free low-temperature solder. The solder comprises, by mass, 0.001-58.0% of bismuth, 0.001-1.0% of silver, 0.001-2.0% antimony, 0.001-0.1% of indium, 0.001-0.15% of phosphorus, 0.001-0.08% of germanium, 0.001-0.015% of beryllium, 0.001-0.015% of cerium and the balance tin. Compared with the prior art, when welding is carried out at the temperature of 139DEG C to 200DEG C, little oxidation slag is generated, the surface of a tin furnace can be kept bright basically without oxidation at the temperature, thesolder can not be oxidized within 50 seconds at 200-260 DEG C, so that the welding efficiency is greatly improved, and the damage to electronic components of a PCBA board is reduced; the low-temperature solder is good in oxidation resistance; and in the welding process, compared with a common Sn-Ag-Cu system, the solder has fewer welding defects, the surfaces of welding spots are very light-bright, the welding spots are full, continuous welding does not occur, so that the welding quality is effectively improved, and the solder and the method are environment-friendly and safe.

The invention discloses a welding process of the longitudinal seam of a blast furnace shell. The welding process has the advantages that the welding gun of carbon dioxide arc welding full-function equipment is clamped to an automatic welding machine, the matched welding process is provided, welding cracks on high-strength steel materials can be eliminated effectively, and accordingly the high-quality welding seam and the stable welding structure can be obtained; the requirements of high-strength steel in actual use are sufficiently satisfied; in addition, the welding process is simple to operate, low in cost and investment, capable of satisfying field actual requirements and high in work efficiency.

The invention discloses a forming and processing method of a titanium alloy high-pressure seamless gas cylinder for ships. The method comprises the following steps: forging a forging blank at the forging temperature of 800-960 DEG C; performing powerful spinning on the blank to machine a cylinder section at the heating temperature of 550-750 DEG C; performing powerful spinning to form the cylindersection; performing core-mold-free hot spinning to form a head end socket; and performing seamless gas cylinder solid solution, aging heat treatment and bottle opening machining. The product is goodin quality and has no welding defects and bottom end socket incomplete fusion defects of a traditional method; the product is high in reliability and fatigue resistance and long in service life; and the material utilization rate is high, and the manufacturing cost is low.

The invention discloses a resistance spot welding method for matching of a steel plate containing super-strong thermal forming. The method comprises the following steps: 1) a correspondingly matched critical splash current I0 is found out on the basis of matching of super-strong thermal forming steel by adopting monopulse welding; 2) welding pulse parameters are determined according to the number j of matched steel plates to be welded, wherein j is an integer 2 or above; and 3) an intermediate frequency direct current spot welder is adopted to conduct welding according to the determined parameters and the time sequence of pre-pressing, preheating, welding, tempering and pressure maintaining. According to the resistance spot welding method, the welding nugget with the large enough diameter can be stably formed on the basis that obvious welding defects are not generated, a welding process window larger than 1.5 kA (an existing window generally does not exceed 0.5 kA, and a process window needed by actual production is larger than 1 kA) is obtained, and the joint strength is obviously improved (the tensile-shear strength is larger than 21 kN, and an existing process joint does not exceed 16 kN).

This method for manufacturing flux-cored wire involves a step for filling flux into the inside of a steel plate while forming the steel plate into a cylindrical shape, a step for joining the two endsof the steel plate to obtain a steel pipe, and a step for rolling and annealing the steel pipe to obtain a flux-cored wire, wherein the chemical composition of the flux-cored wire is within prescribedranges, and the Sn content, the Sb content, the W content and the Mo content satisfy the relation Sn+Sb > Mo+W. The flux-cored wire according to another embodiment is manufactured by the aforementioned flux-cored wire manufacturing method. The method for manufacturing a welding joint according to another embodiment involves a step for welding using the flux-cored wire manufactured with the aforementioned flux-cored wire manufacturing method.

The invention discloses a manufacturing method for a bearing ball. The manufacturing method specifically comprises the following steps that (1) blanking and upsetting of a billet are conducted; (2) edge removing is conducted, specifically, mould casting overspill is removed from the spherical billet obtained in the step (1), and thus a coarse ball is obtained; (3) heat treatment is conducted, specifically, the coarse ball is carburized and quenched; (4) grinding machining is conducted, specifically, a heated coarse ball billet is coarsely ground and accurately ground sequentially, thus a ground ball is obtained, and then the ground piece is subjected to annealing treatment, surface passivation treatment and lubricating treatment techniques sequentially; and (5) polishing is conducted, specifically, a polishing machine and a polishing agent are used for polishing treatment, and thus the bearing ball is obtained. Through the technique, the yield is high, the technique is simple, the bearing ball is manufactured, precise net shaping of a product is achieved, fracturing is avoided in the using process, and the service life of a bearing is prolonged.

The invention relates to an embedded linear friction welding joint defect control method and application thereof, and belongs to the welding manufacturing and repairing technology, and relates to connection or repairing of zero-allowance components. The defect control method comprises the steps that a process plate is fixed to the upper portion of a welded part in the wedge-shaped block entering direction, the process plate is attached to the welded part, and the angle of the welding end of the process plate is not smaller than that of the wedge-shaped block; and the wedge-shaped block installed at the vibration end is embedded into the welding part in the welded part, welding is conducted through a linear friction welding method, welding defects caused by the wedge-shaped block are left on the process plate, and the process plate is removed after welding. According to the method, when the linear friction welding is used for connecting or repairing long components, the joint quality can be ensured, and no defect exists in a welding seam.