Steel material for colored spring, method for producing colored spring, and colored spring

摘要

A steel material for colored spring is formed with a metallic deposit on the surface. The metallic deposit contains copper, zinc, and chrome. In an annealing process, copper and zinc diffuse in the deposit to exhibit a gold color tone while chrome is oxidized to exhibit dark gray color tone. The combination of these color tones exhibits a beautiful black color tone which is distinguishable from normal spring. The deposit improves the formability in the spring shaping process.