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AssigneeNHK Spring Co., Ltd.
InventorsToshiyuki AKANUMA, Tohru SHIRAISHI, Yohei IWAGAKI, Keita TAKAHASHI, Shun HIRAI
Estimating the term…
A compression coil spring includes a steel wire material containing, hereinafter in weight %, 0.5 to 0.7% of C, 1.2 to 3.0% of Si, 0.3 to 1.2% of Mn, 0.5 to 1.9% of Cr and 0.05 to 0.5% of V as necessary components, one or more kinds selected from not more than 1.5% of Ni, not more than 1.5% of Mo and not more than 0.5% of W as freely selected components, and iron and inevitable impurities as the remainder; the C-condensed layer which exceeds the average concentration of C contained in the steel wire material exists at a surface layer part, and the thickness of the C-condensed layer is within 0.01 to 0.05 mm along the entire circumference of the steel wire material.
A compression coil spring, comprising a steel wire material containing, hereinafter in weight %, 0.5 to 0.7% of C, 1.2 to 3.0% of Si, 0.3 to 1.2% of Mn, 0.5 to 1.9% of Cr and 0.05 to 0.5% of V as necessary components, one or more kinds selected from not more than 1.5% of Ni, not more than 1.5% of Mo and not more than 0.5% of W as optional components, and iron and inevitable impurities as the remainder,
A method for production of a compression coil spring, comprising:
Dependencies are inferred from the claim text.