Induction Preheat Welding Steel Rods

Induction preheat welding steel rods applications

Objective To preheat steel rods to 500 ºF (260 ºC) for a welding application for a major equipment manufacturer Material: Customer supplied steel pins (varying, on average 2”/51mm) Temperature: 500 ºF (260 ºC) Frequency: 100 kHz Equipment: DW-HF-45kW 50-150 kHz induction heating system equipped with a remote heat station containing eight 1.0 μF capacitors - A multiple position two-turn induction heating coil designed and developed specifically for this application Induction Preheating Process: The steel rod was loaded into the coil, and the heat was turned on. The part reached 600 ºF (316 ºC) within one minute. The power was turned off and the rod was monitored for 30 seconds to ensure the outside layer did not drop below 500 ºF (260 ºC). Based on the Application Lab’s experiences and testing, the longer the heating time, the less power is required. Additionally, the longer the heating time, the longer the outside temperature remained above 500 ºF. In light of that, there are additional possibilities when it comes to power supplies, from a 15kW induction heater with a two-position coil that has a heating time of two minutes, to a 45kW induction heating system with a four-position coil and a heating time of one minute. Results/Benefits  Precise heating: The customer is looking at switching from flame, as induction can offer more precise, repeatable heating - Penetration: Induction does a superior job penetrating the pin when compared to a torch, which is critical to preheating for welding - Speed: Induction enables fast heating which can boost production compared to torch heating - Part quality: A torch can make the part brittle, which makes induction advantageous - Work environment: Induction preheat welding is a safer heating method that introduces less heat into the workplace than a flame does

Induction Preheating

What is induction preheating?

Induction preheating is a process where materials or workpieces are heated by induction prior to further processing. The reasons for pre-heating vary. In the cable and wire industry, cable cores are pre-heated before insulation extrusion. Steels strips are pre-heated prior to pickling and zinc coating. Induction preheating also softens metals before bending, and prepares tubes and pipes for welding. Mobile preheating solutions facilitate onsite repairs of bearing assemblies. What are the benefits? DAWEI Induction preheating systems are extremely efficient, resulting in major energy savings. When preheating steel strips and cable and wire, diode rectifiers ensure a constant power factor of 0.95, thus eliminating reactive power costs. Cycle times are short, too. And continuous automatic matching means a single coil can handle wide production ranges. Induction preheating systems are compact and easy to integrate into existing or planned production lines. Where is it used? Induction preheating is employed in the automotive, mechanical, aeronautical, electrotechnical, white goods and shipbuilding industries. A major area of use is preheating for welding. Our MYD series air cooling induction heating systems are used in the offshore sector for onsite weld preheating. MYD series air cooling heating units are also frequently flown to oil platforms and airports to perform repairs and maintenance. What equipment is available? The MYD air cooling induction heating systems are primary used for preheating weld heating treatment process.