Method classification

Gas welding

The combustible gases used in gas welding are the same as those used in gas cutting、 mainly including acetylene、 liquefied petroleum gas (propane、 butane、 propylene、 etc.)、 and hydrogen、 with oxygen as the combustion gas The welding wire used for gas welding serves as a filler metal、 forming the weld metal together with the melted base metal during welding. Therefore、 welding wires with corresponding composition or performance should be selected based on the chemical composition and mechanical properties of the workpiece、 and sometimes strips cut from the welded plate can also be used as welding wires When welding non-ferrous metals、 cast iron、 and stainless steel、 welding powder (flux) should also be used to eliminate the refractory oxide film and other impurities covering the surface of the welding material and molten pool、 and form a layer of slag on the surface of the molten pool to protect the molten pool metal from oxidation、 eliminate gases、 oxides、 and other impurities in the molten pool、 improve the fluidity of the molten metal、 ensure smooth welding、 and ensure quality and formation Gas welding is mainly applied to the welding of thin steel plates、 low melting point materials (non-ferrous metals and their alloys)、 cast iron parts、 hard alloy cutting tools and other materials、 as well as repair welding of worn and scrapped vehicle parts、 flame correction of component deformation、 etc The advantage of gas welding is its simple equipment (oxygen cylinder、 acetylene cylinder、 tempering protector、 welding torch、 pressure reducer、 oxygen、 acetylene、 conveying pipe、 etc.) and flexible use; Has good adaptability for welding cast iron and some non-ferrous metals; When welding is needed in areas with insufficient power supply、 gas welding can play a greater role. Its disadvantage is low production efficiency; The deformation and heat affected zone of the workpiece are relatively large after welding; It is difficult to achieve automation [1]  

Arc welding

Arc welding

Arc welding is the most widely used welding method in industrial production. Its principle is to use the heat generated by arc discharge (commonly known as arc combustion) to melt the welding rod and workpiece together and form a weld after condensation、 thereby obtaining a solid joint welding process. When arc welding low carbon steel or low alloy steel、 the temperature of the central part of the arc can reach 6000~8000 ℃、 and the temperature of the two electrodes can reach 2400~2600 ℃

1) Manual arc welding

Manual arc welding can be used for multi-position welding such as flat welding、 vertical welding、 horizontal welding、 and overhead welding.

2) Submerged arc welding

Submerged arc welding is also a welding method that uses the arc as a heat source.

① high thermal efficiency、 large melting depth、 and smaller groove of the workpiece、 reducing the amount of filler metal ② High welding speed、 when welding steel plates with a thickness of 8-10mm、 the single wire submerged arc welding speed can reach 50-2000px/min The presence of welding flux not only separates the contact between molten metal and air、 but also slows down the solidification of the molten pool metal、 reducing the possibility of defects such as pores and cracks in the weld seam However、 due to the use of granular flux、 this welding method is generally only suitable for flat welding positions and cannot directly observe the relative position of the arc and groove、 which can easily cause welding deviation. Additionally、 it is not suitable for welding thin plates with a thickness less than 1 mm Due to the large penetration depth、 high production efficiency、 and high degree of mechanization of submerged arc welding、 it is suitable for welding long welds in medium and thick plate structures. It is widely used in manufacturing departments such as shipbuilding、 boilers and pressure vessels、 bridges、 lifting machinery、 railway vehicles、 engineering machinery、 heavy machinery and metallurgical machinery、 nuclear power plant structures、 and marine structures、 and is one of the most commonly used welding methods in welding production today. The materials that can be welded by submerged arc welding have developed from carbon structural steel to low alloy structural steel、 stainless steel、 heat-resistant steel、 and some non-ferrous metals、 such as nickel based alloys、 titanium alloys、 and copper alloys

Function of testing report:

1. Project bidding: Issue authoritative third-party CMA/CNAS qualification report

inspection and testing process:

1. Telephone communication and confirmation of requirements

Testing and testing characteristics:

1. The testing industry is fully covered、 meeting different testing needs

3. Engineers provide one-on-one services to make testing more accurate

4. Free initial testing、 with no testing fees charged

5. Self service order delivery for free on-site sampling