Electron beam cladding of WC-12 percent Co alloy powder

Abstract

The formation of WC coated layer on the surface of mild steel plate was carried out with WC-12 percent Co alloy powder and electron beam. An electron beam welder of maximum power of 30 kW and accelerating voltage of 40 kV was used as the heat source. The experiments were carried out with various alpha value, which is a parameter to determine the focusing of electron beam. The layer of WC-Co was homogeneously formed without causing any heat damage to the mild steel substrate when alpha value was properly controlled. The layer of WC-Co, which is difficult to be coated by thermal spraying method, could be cladded with electron beam at high speed and without any oxidation.

軟鋼表面上へのWC被覆層形成を、電子ビームとWC-12%Co合金粉を用いて行った。最大出力30kW、加速電圧40kVの電子ビーム溶接機を熱源として用いた。電子ビーム集束を支配するパラメータαをいろいろに変えて実験した。αを適切に制御すれば、WC-Co層は軟鋼基板に、熱損傷を引き起こすことなく、均一に形成された。熱溶射法では被覆が困難なWC-Co層も、電子ビームを用いれば、高速に酸化を起こさずに張り合わせることができた。