Why is it that when welding, people will not be electrocuted when they touch the iron of electric we

Electric shock is to form a circuit of electric current, and it will only occur when an electric current flows through the human body. The voltage of electric welding is only 20 to 60 volts. And there is no composition loop. Therefore, it touches the iron block of electric welding.

There will be no electric shock either. But if you hold the two poles in each hand. There will still be an electric numbness feeling. There is still a certain danger beyond 36 volts.

In our country, welding operations need to be licensed, welders are the type of work that belongs to the access category, in the professional qualifications of skilled personnel, only five of the 81 types of work in the access category, welders are one of them, and the actual situation is that most of the industry practitioners are unlicensed operations. With the continuous standardization of technology and the relevant requirements of the industry, more and more people want to take a welding certificate, the advantage of the certificate is still very large, first of all, the salary of the certificate and the non-certificate are very different, often able to reach more than double or higher level. Therefore, the issue of short-term welder training has naturally become a concern for practitioners.

Welding as an industrial "tailor" is a very important means of processing in industrial production, the quality of welding plays a decisive role in the quality of the product, so, what is the future development of welding technology?

Industry outlook. With the development of production, welding is widely used in aerospace, aviation, nuclear industry, shipbuilding, construction and machinery manufacturing and other industrial sectors, in China's economic development, welding technology is an indispensable means of processing. After entering the 21st century, welding is an important part of the manufacturing industry, and the rapid development, so it has brought unprecedented development opportunities to the welding industry.

At present, China consumes 300 million tons of steel every year (about tons of welded structure), and needs about 750,000 welding machines, and the welding industry will continue to grow in the next 8 10 years.

The reason why you can't get touched when you reach out and touch it during welding is because the voltage is very low during welding.

Electric welding is a welding operation that uses the welding rod to melt the metal parts at high temperature through the arc to the place where they need to be connected. The working principle is: through the commonly used 220V or 380V voltage, through the electric welding machine.

The transformer lowers the voltage, enhances the current, and allows the electrical energy to generate a huge arc heat to melt the electrode and the steel, and the electrode melting makes the steel more integrated.

Key points for the selection of welding wire.

The selection of welding wire should be based on the type of steel to be welded, the quality requirements of the welded parts, the welding construction conditions (plate thickness, groove shape, welding position, welding conditions, post-welding heat treatment and welding operation waiting), cost, etc.

The order to be considered in the selection of welding wire is as follows:

1. Select the welding wire according to the steel type of the welded structure For carbon steel and low-alloy high-strength steel, it is mainly according to the principle of "equal strength matching" to select and meet the mechanical properties.

Welding wire as required. For heat-resistant steels and weathering steels.

The main focus is on the consistency and similarity of the chemical composition of the weld metal and the base metal to meet the requirements of heat resistance and corrosion resistance.

2. According to the quality requirements of the welded parts (especially the impact toughness.

The selection of welding wire is related to the welding conditions, groove shape, shielding gas mixing ratio and other process conditions, and it is necessary to select welding materials to achieve maximum welding efficiency and reduce welding costs under the premise of ensuring the performance of welded joints.

3. According to the on-site welding position corresponding to the thickness of the welded workpiece, the diameter of the welding wire used is selected, the current value used is determined, and the welding wire grade suitable for the welding position and current is selected with reference to the product introduction information and use experience of each manufacturer.

The welding process performance includes arc stability, spatter particle size and quantity, slag removal, weld appearance and shape, etc. For the welding of carbon steel and low-alloy steel (especially semi-automatic welding), the welding method and welding material are mainly selected according to the welding process performance.

The above content reference: Encyclopedia - electric welding.

Encyclopedia - Welding.

The electrostatic welding will ignite when the electrocuted iron block is connected, why does the electrode weld on the steel plate not react?

The electrostatic welding will ignite when the electrocuted iron block is connected, why does the electrode weld on the steel plate not react? Hello dear, this has a relationship with the material, iron is harder than steel plate, if you weld, the current will be large, it is easy to produce sparks, steel plate, the current is relatively small, there will be no sparks, there are also the following two reasons; 1. There is no cleaning or cleaning during welding. When using the welding machine, it is necessary to pay attention to the cleaning of the workpiece, so that the welding will be better.

2. It may be because the pressure distribution on the contact surface between the spot welding machine and the welding item is uneven, resulting in high local current density, which leads to the early melting of the welding squeeze and the spatter situation. Hope it helps.

The voltage is very low when welding, about 40 volts. When working, the human body is equivalent to being connected in parallel with the neutral line, and the resistance of the human body is much greater than the resistance of the neutral line, so the cable flowing through the human body is very small.

The welding process must apply pressure to the weldment, which belongs to the processing of various metal materials and some metal materials. The metal material with a lower melting point than the base metal is used as the brazing metal, and the liquid brazing metal is used to wet the base metal, fill the joint gap, and diffuse with the base metal to realize the link weldment. It is suitable for the welding of various materials, and also suitable for the welding of different metals or dissimilar materials.

It is basic common sense that the workpiece can not be touched when it is welded.

First of all, it is for safety reasons, the electric welding machine.

Although the voltage is not high, the no-load is also 70V, which may be electrocuted; The temperature of the thermal arc can reach more than 6,000 degrees, and the workpiece may reach six or seven when welding, and it may be scalded by direct touch.

If you want to move the workpiece, it is advisable to wear labor protection gloves and labor protection shoes.

Secondly, the arbitrary movement and change of position of the workpiece during welding may lead to the destruction of the weld pool and affect the welding quality.