This chapter of the free Fluxtrol induction heating course walks through case story – surface hardening of truck axle in 11 slides. View the slides below, or skim the outline and slide text.
Chapter outline
- Problem Description and Specifications
- Step 1: Analysis of Results Obtained with
- Step 2a: Simulation of the Process
- Step 2 a: Temperature Distribution at the End of the Dwell
- Step 2b: Simulation of the Process
- Temperature Distribution at the End of the
- Step 3: Development of Optimized Coil
- Temperature Distribution at the
Slide text
Problem Description and Specifications
- The customer contacted Fluxtrol Inc. for the following reasons:
- They were unable to produce good parts for a contract they had won
- The problem was the new part had a sharper fillet than other parts they had worked with before X In order to get the required depth in the fillet, they had to severely overheat the area (X) just above it resulting in almost through hardening
Step 1: Analysis of Results Obtained with
- Existing Equipment
- Customer had the necessary equipment (dual-spindle scanner and powersupply 400kW,1kHz)
- Customer had 2 standard scan coils that they attempted to use for the process
- Single turn coil came closer to achieving the desired results, but production rate was low during scanning
- Twoturn coil could produce parts faster, but could not properly heat the fillet area
Step 2a: Simulation of the Process
- with Existing Single Turn Coil Simulation of the process with a singleturn coil without a magnetic flux controller clearly showed overheating of the stem near fillet area (in good agreement with tests results) Temperature distribution and magnetic field lines at the end of dwelling period Flux 2D program
Step 2 a: Temperature Distribution at the End of the Dwell
- Temperature range 20–1150C Temperature range 800–1150C Results: Marginal depth in the radius, severe overheating in the area above the radius (temperature over 1150C,which would continue to grow in the beginning of the scanning process)
Step 2b: Simulation of the Process
- with Existing Two-Turn Coil Temperature distribution and magnetic field lines at the end of dwell Flux 2D program
Temperature Distribution at the End of the
- Dwell with Two-Turn Coil Temperature range 20–1135C Temperature range 800–1135C Results: Insufficient depth in the radius and short pattern on fillet, severe overheating in the area above the radius (temperature over 1130C,which would continue to grow in the beginning of the scanning process).
Step 3: Development of Optimized Coil
- Based on results of computer simulation and previous experience it was decided to design a twoturn coil with Fluxtrol concentrator on the lower turn.
- This design provides a favorable temperature distribution with required hardness depth on fillet and well controlled preheating of the stem area by the upper turn.
- Optimal temperature distribution was achieved by variation of crosssections of copper and magnetic concentrator made from Fluxtrol “A”.
- Temperature distribution and magnetic field lines at the end of dwell
Temperature Distribution at the
- End of the Dwell with Optimized Coil Temperature range 20–1020C Temperature range above 800C corresponding to a total hardness depth Results: Good depth in the radius, no significant overheating in the area above the radius (temperature less than 1020 C); high scan speed/ production rate