Core Annealing

The annealing process, which removes stress from the steel, is critical to insure the core will deliver optimum accuracy and minimum excitation loss. Cores are tempered in a controlled nitrogen atmosphere to prevent oxidation. Temperature escalation is time-controlled until reaching 1500° F. The soak time is determined based on mass and stack configuration. Throughout the process, fully automated controllers provide full time monitoring of temperature, nitrogen level and cycle time.

Achieving a flawless annealing process is an art which requires a precise combination of temperature, time, and atmosphere. At Meramec, forty years’ experience has refined and perfected this art.

Our first furnace, which was designed in 1969 by Meramec’s founder, Andrew Sanazaro Sr., has evolved to our latest design of energy efficient furnaces which require 40% less power consumption. We do not use conventional all-purpose ovens.

Our large batch ceramic furnaces are built in-house and designed specifically for annealing instrument transformer cores.