Productive wear plate surface overlay welding machine

Surfacing welding is a welding method in which metal is melted by electric welding or gas welding and piled on tools or machine parts. Usually used to repair worn and cracked parts. As an economical and fast process method for surface modification of materials, surfacing welding is more and more widely used in the manufacturing and repairing of parts in various industrial sectors. To play the role of the surfacing layer most effectively, it is hoped that the surfacing method adopted has a smaller dilution of the base material, higher deposition speed, and excellent surfacing layer performance, that is, high-quality, efficient, and low-dilution surfacing technology.

The weld overlay refers to the metal cladding layer used to protect the surface of the component from corrosion or other damage. The most widely used chemical equipment is the use of welding methods (such as strip surfacing) to surfacing corrosion-resistant austenitic stainless steel on the inner surface of the equipment. For example, the weld overlay on the inner wall of the urea synthesis tower uses ultra-low carbon molybdenum-containing austenitic stainless steel, which can greatly slow down the corrosion of urea to the equipment.
The inner walls of various high-temperature and high-pressure hydrogenation reactors are welded with chromium-nickel austenitic stainless steel, which can effectively prevent the high-temperature hydrogen corrosion of the steel surface by hydrogen. It should be noted that there must be proper operating procedures to prevent the weld overlay from peeling off the base steel.

The purpose of surfacing welding is to deposit a layer of wear-resistant, corrosion-resistant, and heat-resistant metal on the surface or edge of the workpiece. Surfacing welding has significant economic benefits for increasing the service life of parts, using materials reasonably, improving product performance, and reducing costs. Different workpieces and surfacing electrodes must adopt different surfacing welding processes to obtain satisfactory surfacing results.

Almost any welding method can be used for surfacing welding, from the earliest used gas welding surfacing, electrode arc welding surfacing, to the present, various semi-automatic and automated surfacing methods have been developed. Each surfacing method has its own advantages and disadvantages. The characteristics of commonly used surfacing methods are as follows:
(1) Manual arc surfacing. It is characterized by simple equipment, flexible process, and is not limited by the welding position and the surface shape of the parts; the disadvantage is that the productivity is low, the dilution rate is high, and it is difficult to obtain a thin and uniform surfacing layer. The working conditions are poor.
(2) Manual oxygen-acetylene flame surfacing welding. The temperature of the oxygen-acetylene flame is low, and a very small dilution rate and a uniform thin layer as small as 1 mm can be obtained. This method is simple, flexible, and low-cost. The disadvantage is low productivity and high labor intensity.
(3) Submerged arc welding (including submerged arc surfacing and electro slag surfacing, etc.) is a method in which the arc burns under the flux layer for welding. Its inherent advantages such as stable welding quality, high welding productivity, no arc, and little smoke, make it the main welding method in the production of important steel structures such as pressure vessels, pipe section manufacturing, box beams, and columns.
(4) The characteristics of gas shielded surfacing welding are: light oxidation of the welding layer, high quality, high efficiency, small heat-affected zone, and the open arc is convenient for construction observation.
(5) The argon tungsten arc welding surfacing has the advantages of good visibility, easy control of the shape of the surfacing layer, stable arc, no spatter, good quality of the surfacing layer, and less heat absorption and small deformation of the manual argon tungsten arc welding surfacing workpiece, Automatic argon tungsten arc welding surfacing can obtain higher quality surfacing layer. The surfacing material can be a solid wire or flux-cored welding wire, but the surfacing efficiency is low, and it is suitable for surfacing small and complicated workpieces.
(6) Plasma arc surfacing, the temperature of plasma arc is very high, so it can surfacing welding refractory materials, and can increase the surfacing welding speed, the minimum dilution rate can reach 5%, the surfacing layer thickness is 0.5~8mm, the width is about 3 ~40mm, this method of surfacing welding with low dilution rate and high deposition rate, but the equipment cost is higher, and there is strong ultraviolet radiation and ozone pollution space during surfacing, so protective measures must be taken. Often used in mass production with high-quality requirements.
(7) Electroslag surfacing is a surfacing process that uses the resistance heat of conductive slag to melt the surfacing material and base metal. At present, electrode electro slag surfacing welding is more commonly used, which has a 50% higher production efficiency and lower dilution rate (can be controlled below 10%) than electrode submerged arc surfacing, as well as good weld formation. There are defects such as slag inclusions. The surface unevenness is less than 0.5mm, and single-layer surfacing can meet the requirements without machining. Suitable for large-area surfacing welding on the inner wall of pressure vessels. When electro slag surfacing is used for surfacing of workpieces working in hydrogen-containing media, due to the low welding speed and large heat input, the boundary layer between the base material and the surfacing layer has coarse grains, making the surfacing layer resistant to Hydrogen-induced peeling performance decreases. Due to its large heat input, it is generally only suitable for surfacing thick-walled workpieces larger than 50mm.

Mold manufacturing: roughening the surface of plastic molds to increase aesthetics and service life; repairing the parting surface of helmet plastic molds by surfacing; strengthening the surface of shunt cones of aluminum alloy die-casting molds; repairing and strengthening mold cavities such as out of tolerance, wear and scratches.
Plastic rubber: repair of rubber and plastic machinery parts, out-of-tolerance, wear, and repair of molds for rubber and plastic parts.
Aerospace: aircraft engine parts, turbines, turboshaft repair or repair, rocket nozzle surface strengthening repair, aircraft outer plate component repair, artificial satellite shell strengthening or repair, local carburizing strengthening of titanium alloy parts, iron-based superalloy parts Local carburizing strengthening, magnesium alloy surface infiltration A1 and other anti-corrosion coatings, magnesium alloy parts local defect surfacing repair, nickel-based/cobalt-based superalloy blade workpiece local surfacing repairs, such as blade crown damping surface and blade tip Wear and ablation of guide vanes.
Manufacturing and maintenance: In the automobile manufacturing and maintenance industry, it is used for compensation and repair of cams, crankshafts, pistons, cylinders, brake discs, impellers, hubs, clutches, friction plates, exhaust valves, etc., and repairs and repairs surface weld bead defects of automobile bodies.
Ship power: repair of electric crankshafts, bushings, bushings, electrical components, resistors, etc., welding of electric railway locomotive wheels and bottom track connecting piece, electroplating factory conductive roller, metal oxidation treatment copper and aluminum electrode production welding.
Machinery industry: correcting out-of-tolerance workpieces and repairing machine tool guides, various shafts, cams, hydraulic presses, hydraulic press plungers, cylinder walls, journals, rollers, gears, pulleys, spring forming mandrels, plug gauges, ring gauges, various Class rollers, rods, columns, locks, bearings, etc.
Foundry industry: repairing defects such as sand holes and pores in iron, copper, and aluminum castings, repairing wear and tear of aluminum models.