This article lists the advantages and disadvantages of laser welding machines and 7 types of traditional welding machines. An in-depth understanding of the differences between these two welding systems can help you choose the most suitable working partner.
Handheld Laser Welding Features
Working Principle
The main components of the laser welding systems are the laser source, the welding head, the wire feeder and the chiller. The welding process is a heat conduction type. The laser beam melts the welding wire and fills the gaps in the material to achieve precise and fast welding.
Advantage
- High precision and aspect ratio: Because the focused light spot is tiny, the weld seam can be positioned with high precision. The weld seam becomes deep and narrow. The melting process occurs extremely quickly. Thermal deformation and heat-affected zones are small and almost negligible.
- High weld strength: the melting zone is less polluted, making the weld strength and toughness equal to or even better than the parent metal.
- Simple operation: The laser welding equipment has a welding gun and is equipped with radiation-proof glasses to work. There is no odour or harmful gases during the working process, and the working environment is perfect. The welding head is very light, about 0.8 kg, even if worked for a long time. You won’t feel tired. The technical requirements for workers are relatively small, and they can be employed with simple operations.
- Multi-angle welding: The laser welder is generally equipped with eight welding nozzles, and the suitable welding nozzle can be replaced according to the required welding angle. But for an experienced operator can complete flat welding, butt welding, fillet welding, and more special-shaped interface welding with only one welding nozzle.
The performance of the lazer welding machine is relatively good; there are few failures during the production process, and the maintenance cost is low.
Disadvantage
- Workpieces with limited welding depth and penetration thickness far exceeding 19mm are unsuitable for handheld laser welders.
- The handheld fiber laser welder cannot be installed on the production line.
- The one-time investment is relatively high. However, with the popularity of welding machines, the technology has become more and more mature in recent years, and the cost-effectiveness of the devices is also very suitable.
- Inert gas is required to assist welding such as helium, argon, and nitrogen. Choose different gases according to your metal materials.
- There are requirements for welding materials, the penetration depth is 5mm, and the welding seam is less than 2mm. Not suitable for welding rigid structures.
7 Traditional Welding Techniques And Features
Traditional wsolding can be divided into fusion welding, pressure welding and brazing according to the characteristics of the welding process. I’ve picked out seven common types of welding that we can look at in depth.
1, Oxyacetylene Flame Gas Welding (G; 311)
During gas welding, the combustion of flammable gas and oxygen creates a flame that melts the material. The welding rod is usually fed into the melting zone by hand to fill the welding groove. The flame gases cover the molten pool and protect it from the air.
- Welding materials: mainly used for welding of non-alloy and low-alloy steel plates and pipes (can also be used for welding of cast iron)
- Weldable plate thickness: approximately from 0.8mm to 6mm.
2, Gas Tungsten Arc Welding
Gas tungsten arc welding methods are divided into three types:
- Tungsten inert gas welding (WIG / TIG),
- Tungsten plasma welding (WP)
- Tungsten hydrogen atomic welding (WHG).
It use welding wire as filler material for welding. Inert protective gases such as argon, helium or their mixed gases can effectively isolate the air. They are insoluble in metals and do not react with metals. It can successfully weld easily oxidized non-ferrous metals
The heating of the workpiece is concentrated on a slight arc area, so it is particularly advantageous for welding thin plates. During welding, neither slag is formed, nor oxidation occurs on the surface of the weld.
Weldable Scope
Suitable for all-position connection welding of steel and non-ferrous metals within the workpiece thickness range of 0.5 to 4.0mm and surfacing welding.
Advantage
- Because the weld is well protected, the weld metal has high purity and good performance;
- The heating is concentrated during welding, so the deformation of the weldment is small;
- The arc stability is good, and the arc can burn stably even at small currents (<10A).
- The welding process is easily mechanized and automated.
Disadvantage
- Argon is expensive, so production costs are relatively high.
- Higher requirements for workpieces. The workpiece needs to be cleaned well before welding.
- The limited current-carrying capacity of tungsten electrodes and the weld penetration depth are shallow. It is only suitable for welding thin and ultra-thin plates (<6mm).
3，Gas Metal Arc Welding（MSG；MIG 131/MAG 135）
Both MIG and MAG are gas arc welding methods.
The shielding gas, welding current and welding wire are delivered to the welding area through the hose bundle. The visible burning arc temperature between the welding wire and the workpiece is about 10,000°C. The welding wire melts into droplets.
When welding non-ferrous metals, use inert gas (noble gas) to protect the molten pool from air intrusion;
When welding carbon steel, low and high alloy steel, the conductive nozzle is generally used to transmit it to a location close to the arc directly. This allows the welding wire to have a higher current carrying capacity (for example, a welding wire with a diameter of 1mm can carry 40~ 200 Amps of welding current), increasing the deposition rate.
Application scope:
Suitable for all-position connection and surfacing welding within the workpiece thickness range of 0.6 to 100mm.
Advantage:
- Like TIG welding, it can weld almost all metals. It is especially suitable for welding aluminum and aluminum alloys, copper and copper alloys, stainless steel and other materials.
- Welding permits high current density, high penetration, and rapid filler metal deposition. When used to weld metals such as thick aluminum sheets and copper, productivity is higher than with TIG welding and weld distortion is less than with TIG welding.
- It can be connected with DC reversely and has a good cathode atomization effect when welding aluminum and its alloys.
Disadvantage:
- Inert gases are expensive, so the cost is high.
- It is very sensitive to the oil and rust of the base metal and welding wire, It is prone to pores.
4, Submerged arc welding (UP; 12)
Working Principle
The arc burns beneath a layer of granular flux. welding current intensity 200~2000 amps. The energy of the arc melts the workpiece, and the penetration depth is deep. The welding current is directly transmitted to the end of the welding wire through the conductive tip. This allows the welding wire to have a larger current carrying capacity, increasing the deposition rate.
Scope of application
Mainly used for connecting and welding long welds of carbon steel, low alloy steel and high alloy steel in horizontal positions (including boat-shaped positions) with a workpiece thickness of 8mm or more;
It has been widely used mainly in container manufacturing, steel structure, shipbuilding industry and vehicle manufacturing.
Advantage:
- The weld quality is high, and the arc and molten pool are protected by slag. It reduces the possibility of defects such as pores and cracks in the weld. The welding parameters can be kept stable through automatic adjustment.
- High productivity: Compared with the conductive position of the electrode in manual arc welding, the conductive wire length (protrusion) is short and stable, which increases the arc power, penetration capacity, and wire melting rate accordingly. Due to the heat insulation effect of flux and slag, the welding speed of submerged arc welding is greatly improved. Under certain conditions, the 10~20mm steel plate can be welded through and formed at one time. The maximum welding speed can reach 60~150m/h.
- Low welding cost and wide range. There is no arc radiation during the welding process, and there is a tiny metal splash. The primary role of the welder is to operate the welding machine, and the working conditions are greatly improved.
Shortcoming:
- It can only be used for horizontal welding.
- The main flux components are metals and non-metal oxides such as MnO and SiO2. It is difficult to weld highly oxidizing metals and their alloys, such as aluminium and magnesium.
- It is only suitable for long-welding seam welding, and the productivity of short-welding seam welding is not as good as manual arc welding.
- When the current is less than 100A, the arc stability is poor, so it is unsuitable for welding thin plates with a thickness of less than 1mm.
5, Resistance spot welding (RP; 21)
Working principle
Resistance spot welding uses current to pass through columnar electrodes to generate resistance heat between two overlapping welding parts. It heats the welding parts to a melted state and then applies pressure to form a welding joint.
Application
Suitable for welding steel or aluminium plates, workpiece thickness ranges from 0.5 to 3.0mm.
Advantage:
- The molten metal is isolated from the air. The metallurgical process is simple.
- The heating time is short, and the heat is concentrated. So, the heat-affected zone is small, and the deformation and stress are also small. There is usually no need to arrange correction and heat treatment processes after welding.
- There is no need for filler metals such as welding rods and wires. Also, there is no need for welding materials such as oxygen, acetylene, and argon, so the welding cost is low.
- Simple operation, easy-to-realize mechanization and automation. They have improved working conditions.
- High productivity, no noise and harmful gases. In mass production, it can be installed on the production line.
Shortcoming:
- There is a lack of reliable non-destructive testing methods. You can only check the Welding quality by destructive testing of process samples and weldments.
- Point and seam welded lap joints increase the weight of the components. The tensile strength and fatigue strength of the joints are both low.
The equipment has high power, a high degree of mechanization and automation, and high cost. Maintenance is more complicated. It also requires separate power distribution.
6，Electrode arc welding (E; 111)
Working principle:
Arc combustion provides the heat source. Manually manipulate the welding rod for welding.
The arc generates high temperatures to melt metal for welding. The temperature of the arc is higher than 4000°C. The welding rods is heated to produce gas and slag. It can protect the molten zone from the harmful effects of the air.
Application scope:
Suitable for all-position welding. Workpiece thickness is above 3mm. Connection welding and surfacing welding of low carbon steel, low alloy steel and high alloy steel. It can also weld dissimilar metals.
Advantage:
- The welding equipments are simple, cheap and lightweight. Low investment and easy maintenance are reasons for its wide application.
- No gas protection is required. The welding rod can generate gas that protects the molten pool and the outside of the weld from oxidation. It also has strong wind resistance.
- Flexible operation and strong adaptability. Can weld special-shaped materials. Welding can be done wherever the welding rod can reach.
Disadvantage:
- Welder training costs are high. Welding quality mainly depends on the welder’s operating skills and experience. Therefore, Regular and frequent welding training is necessary.
- Poor working conditions. Workers are always in a high-temperature baking and toxic smoke environment.
- Production efficiency is low. Electrode arc welding mainly relies on manual operation. The electrode must be replaced frequently during welding, and the weld bead slag must be cleaned frequently.
- Active metals (such as Ti, Nb, Zr, etc.) and refractory metals (such as Ta, Mo, etc.) are susceptible to oxygen pollution. The protective effect of the welding rod is not enough to prevent the oxidation of these metals.
7，CO2 Gas Shielded Welding
Principle:
Use CO2 as the protective gas and the welding wire as the electrode for welding. The welding of the wire is carried out automatically by machinery, and the operator holds the welding gun for welding.
Application:
Suitable for welding low carbon steel and low alloy steel with tensile strength below 600MPa.
Advantage:
- Low cost: the welding cost is about 40% of that of manual arc welding.
- CO2 arc has intense penetration, high welding current density, and high wire melting rate. Generally, there is no need to clean slag after welding, so the productivity of CO2 welding is about 1 to 3 times higher than that of electrode arc welding.
- It can be used for welding in all positions, and the welding quality of thin parts is high, and the welding deformation is small. The arc heat is concentrated, the heating area is small, and the welding speed is fast. The CO2 airflow plays a specific cooling role in the weldment. It prevents burn-through of thin welding parts and reduces welding deformation.
- Strong rust resistance and low hydrogen content in the weld. The tendency of cold cracking is slight when welding low-alloy high-strength steel.
Disadvantage:
- There is a lot of metal spatter during the welding process. Especially when the welding process parameters are not matched properly, it is more serious.
- Do not weld metal materials that are easily oxidized. The wind resistance is weak. Windproof measures are required for outdoor operations.
- The welding arc is substantial, especially when welding with high current. Pay attention to the protection of operators against arc radiation.
Laser Welding VS Traditional Welding Techniques
Application Filed
The hand laser welders are suitable for welding stainless steel, alloys, steel, diamond and other materials or dissimilar materials. They have been used in a variety of manufacturing industries, such as electrical and electronic industries, automobiles, steel, heavy industry, construction machinery and maintenance technology.
Traditional welding methods require the selection of different welding tools according to different scenarios, which has great operational limitations.
Welding Thickness
The Handheld optical fibre welding machines have requirements for welding materials; the penetration depth is 5mm, and the welding seam is less than 2mm. Maximum welding thickness 7mm.
In contrast, gas tungsten arc welding can only weld plates below 4mm, while submerged arc welding is suitable for materials above 8mm.
Thermal Impact
The welding seam of the laser welding machine is beautiful, the heat affected zone is small, and it is not easily deformed and can almost be ignored.
The heat affected zone of conventional welding varies depending on the welding tool chosen. For example, the weld effect of resistance welding is very good.
Security comparison
The operation of the laser soldering machine is very safe, and the position of the laser light is clear. No protective mask is required.
Traditional resistance butt welding will produce a large amount of sparks, which is highly dangerous and requires isolation.
Welding efficiency
The welding speed of the laser fiber welding machine can be flexibly controlled according to the effect.
Traditional welding machines have different plate requirements, and different welding tools target different materials and thicknesses.
Investment
For handheld welding machines, with the popularity of the market, the current price is also very reasonable, and ordinary factories can afford it.
The price of traditional welding equipment varies depending on the application industry. For low-investment machines, the requirements for the environment and operators are very high. Later operation and maintenance costs will also be relatively high.
Summary
The above is our comparison of the working principles, application scope, advantages and disadvantages of the two types of welding systems. You can choose the best welding system for your job. If you want to know more about laser welding machines, please contact us.
FAQ
Laser welding machines have high operational flexibility and can weld materials of any shape. However, it cannot weld very thick materials, so it cannot completely replace traditional welding methods.
The initial investment in a laser welding machine is relatively large, but the later use cost is very low. Compared with manual welding, gas metal arc welding, arc welding and other welding, investing in a laser welding machine is very worthwhile. It has simple operation, good working environment and high efficiency, and can complete more work in a shorter time.
Laser welding machines require inert gas. On the one hand, it can assist welding and make the welding effect better, on the other hand, it can prevent non-ferrous metals from oxidizing.
