There are many welding methods that can be achieved without electrodes.Mainly including flash welding, resistance welding, plasma welding, ultrasonic welding and so on.Used for welding rebar process, generally resistance welding and flash welding.Resistance welded joints are of relatively good quality.Resistance welding is a method to press welder parts between two electrodes and apply an electric current to heat them to a molten or plastic state by using the thermal resistance effect generated by current flowing through the contact surface of workpiece and adjacent areas, so as to form a metal bond.Resistance welding parts are assembled into butt joints, connected with power, and make its end face gradually move close to reach local contact, use resistance heat to heat these contact points (generate flash), make the end metal melt, until the end reaches temperature in a certain depth range, quickly apply the forging force to complete the welding method.

Electroless welding technology is a new welding technology based on self-propagating technology, which can weld metals without power source, air source and large auxiliary equipment.Mainly used in emergency and extreme environment, a new welding and maintenance products.Principle is very simple, it is mainly used for reinforcing steel bar, and small cross section rod bar material, is through the two high-power electrodes (usually copper pad) respectively two workpiece clamping, and electricity, the two workpiece contact, strong current through the workpiece, make it produce a lot of heat, welding can be controlled by a handle of the contact and broken time, contact, artifacts will be melt, react with oxygen, dazzle beautiful, welder can spark according to determine heating temperature, is part of welding materials melt, the pressure and then reuse it.Joint performance is very good, the strength can meet the requirements.

1 the flame brazing

Flame brazing is suitable for brazing carbon steel, cast iron, copper and its alloys.Oxy-acetylene flame is a common flame.

2, resistance brazing

Resistance brazing can be divided into direct heating and indirect heating.Indirect heating resistance brazing is suitable for brazing parts with great difference in thermal physical properties and thickness.

3. Induction brazing

Induction brazing is characterized by fast heating, high efficiency, local heating and easy automation.According to the protection mode, induction brazing in air, induction brazing in shielding gas and induction brazing in vacuum can be divided.