Induction technology offers numerous benefits in many welding applications that require preheating and stress relieving of parts. Induction provides great consistency in
heating
, faster time to temperature of the part, ease of use and safety in operation.
While induction is a commonly used method for heat treatment in pipe fabrication and welding, many people may not realize that this method also offers great flexibility and benefits in welding applications involving other part geometries, including flat plates. To help dispel the notion that induction can be used only for pipe welding, this article discusses some key best practices to help operations achieve success when using induction heating in flat plate applications.
Preheating is an important preparatory operation for certain welding jobs. As the name implies, it is the process of raising the temperature of a part before welding it. This preheat temperature has to be maintained throughout the welding procedure. In some cases it might be necessary to continue heating the part during welding, but sometimes the heat input from the welding itself maintains that temperature. The interpass temperature, which is the base metal temperature maintained between the first and last welding passes, should not fall below the preheat temperature. Preheat is recommended for certain jobs for several reasons. Among these is that it helps stave off moisture from the base metal and weld, which in turn makes the completed part less susceptible to hydrogen cracking.
How To Control Hydrogen in Welding
This resistance heater is designed primarily for controlled annealing of materials after welding to reduce tension and reduce hydrogen content and for preheating before welding up to temperature of 1050 °c.
What is induction welding? induction welding is similar to resistance welding. In resistance welding, however, the current is delivered through contacts to the work piece, instead of induction. The welding form that uses an induction coil energized with a radio-frequency electric current and electromagnetic induction to heat the work piece is what is referred to as induction welding. In most instances both an electrically conductive and ferromagnetic work piece will be acted upon by an electromagnetic field (emf). Eddy currents are used and resistive heating takes place. In ferromagnetic induction welding hysteresis heating occurs. The emf distorts the magnetic domains of the ferromagnetic material.
Inductotherm group companies use electromagnetic induction for melting, heating and welding applications across multiple industries. But what exactly is induction? and how does it differ from other heating methods? to the typical engineer, induction is a fascinating method of heating. Watching a piece of metal in a coil turn cherry red in a matter of seconds can be surprising to those unfamiliar with induction heating. Induction heating equipment requires an understanding of physics, electromagnetism, power electronics and process control, but the basic concepts behind induction heating are simple to understand.