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No.64 (2004/2) >

 
Title :Characteristics of Corrosive Wear of Coated High-Speed Steel Tools
Title alternative :コーティング高速度鋼工具の腐食摩耗特性
Authors :Fukuda, Hideaki
Banshoya, Kaoru
Murase, Yasuhide
Authors alternative :福田, 英昭
番匠谷, 薫
村瀬, 安英
Issue Date :Feb-2004
Abstract :To clarify the characteristics of corrosive wear of coated high-speed steel tools in high moisture-content Douglas-fir (Psuedotsuga menziesii Franco) cutting, tool-life tests were conducted with a whirling disc-machine. Three kinds of coated tools and uncoated tools were prepared. Both rake faces and clearance faces of the tools were coated with either TiN, TiCN, or CrN by physical vapor deposition (PVD) method. The thickness of thin-film for each coated tool was 2-3 μm. In the tool-life tests, electrical-potential of +1 kV, 0 V, or —1 kV was applied to the tool by use of a direct-current power supply. From scanning electron microscope observations conducted after the tool-life tests, delamination of thin-film for each coated tool was viewed. The degree of delamination was the largest under +1 kV, and the smallest under —1 kV. Among measurements of tool wear, edge recession under 0 V for CrN-coated tools was the smallest among all of the tools. The CrN-coated tool was superior to the other tools in reducing the progression of edge recession. The differences in edge recession under —1 kV for the three kinds of coated tools were not detectable. The tool-wear progression under +1 kV for all tools occurred quickly. By regarding edge recession at —1 kV as being caused by a mechanical wear mechanism, the ratio of corrosive wear to the total edge recession under 0 V could be obtained. The value for uncoated tools was 55% and was the largest. The value for CrN-coated tools was 43% and was the smallest.
本研究では,高速度鋼工具のすくい面と逃げ面にTiN,TiCN,またはCrNを被膜した各コーティング高速度鋼工具と無処理工具を用いて,ベイマツ高含水率材の平削り加工を3種類の通電条件下で行い,コーティング高速度鋼工具の腐食摩耗特性を調べた。 工具に直流電圧を与えない0Vの通常切削では,工具摩耗量は無処理工具が最も大きく,CrNコーティング工具が最も小さい工具摩耗量を示した。また,-1kVのカソード電圧下での工具摩耗量は,いずれの工具もカソード防食効果によって著しく小さくなり,通常切削の場合の約1/2の値を示し,供試工具による違いはほとんど認められなかった。さらに,+1kVのアノード電圧下での工具摩耗量は,0Vの場合の約3倍,-1kVの場合の5.1~6.1倍の値を示し,TiNコーティング工具とCrNコーティング工具の工具摩耗量は,無処理工具よりも小さくなっていた。通常切削における工具摩耗に占める腐食摩耗の割合を求めると,無処理工具は約55%,TiCNコーティング工具は54%で無処理工具と大差ないが,TiNコーティング工具は48%であり,CrNコーティング工具は43%で最も小さい値を示した。
Type Local :紀要論文
ISSN :1345-3319
Publisher :琉球大学教育学部
URI :http://hdl.handle.net/20.500.12000/948
Citation :琉球大学教育学部紀要 no.64 p.207 -219
Appears in Collections:No.64 (2004/2)

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