Based in the Czech Republic, Retezárna is a major European chain producer. And helping
the company compete in the global marketplace are three complete EFD Induction
hardening lines. EFD Induction chain hardening specialist Spencer Jones has the details.
The new hardening solution for Retezárna involves two lines for 16-34mm chains, and one for 6-16mm chains. Each line is a complete system, featuring inlet and outlet chain handling mechanisms, power converters, customized induction coils, quenching troughs and PLC control systems.
One key advantage of EFD Induction chain hardening solutions is their comparatively low height. This is due to EFD Induction’s unique coil design. The two large lines are only 7.3 meters high, while the smaller line is approximately six meters in height.
Two of the main benefits of an EFD Induction system are its high productivity and the final quality of the chains. Since installing the new lines, Retezárna has been able to make and sell higher grade chains that command premium prices in world markets.
The quality necessary for high grade chains is difficult to achieve with furnace hardening, due to the uneven heating and cooling inherent in such an inexact process. Induction on the other hand ensures quick and precise heating patterns that are optimized for each chain. Moreover, key parameters such as ramp-up and dwell times, penetration depths and temperatures are reproducible with extreme accuracy.
The minimal process variations of induction heating contribute to consistently uniform product chemistry and mechanical properties. And thanks to induction’s application versatility, this is valid for each phase of the process: pre-heating, austenitizing and tempering.