奥氏体不锈钢加工可转位方肩铣削刀具失效机理研究

Study on Failure Mechanism of Indexable Square Shoulder-milling Tool for Austenitic Stainless Steel

以奥氏体不锈钢0Cr18Ni9为铣削材料,使用薄PVD涂层的硬质合金可转位方肩铣刀进行铣削加工,研究刀具在铣削0Cr18Ni9材料时的失效机理。采用超景深(VH-S30B型)、场发射扫描电镜(SEM:SIGMA500型)和能谱元素分析仪(EDS:Oxford X-aCT型)对刀具失效部分进行形貌分析和元素成分分析。研究表明:刀具的失效机理是粘结磨损、扩散磨损和一定的氧化磨损;刀具失效位于刀尖后刀面、刀尖以及前刀面;刀具后刀面的失效形式以边界磨损为主,最终由于粘结磨损逐渐演变为刀尖后刀面崩缺;刀具刃口失效形式是刀尖崩刃,大量粘结的被加工材料形成负倒棱并参与切削而导致刀尖失效;刀具的前刀面失效主要有PVD涂层大面积剥落和前刀面粘结大量被加工材料两种形式。

Taking the austenitic stainless steel 0Cr18Ni9 as milling material and using the indexable carbide square-shoulder milling inserts with thin PVD coating to milling,research the failure mechanism of milling 0Cr18Ni9 material.Ultra depth of field(VH-S30B),field emission scanning electron microscopy(SEM:SIGMA500)and energy spectrum element analyzer(EDS:Oxford X-aCT)are adopted to analyze the morphology and element composition of the tool failure part.The results show that the failure mechanism of cutting tool is bond wear,diffusion wear and oxidation wear.The failure position of the tool is the back face of the inserts nose,the inserts nose and the front face of the inserts nose;the failure form of the back face of the tool is mainly the boundary wear,and the binding are gradually evolved to the back face of the tool nose.The failure form of the tool edge is the tool nose breaking and a large number of bonded processed materials form negative chamfering and participate in cutting that lead to the failure of the tool nose.The failure of the front face of the tool are mainly two forms,including large area peeling of PVD coating and large amount of processed materials bonded on the front face.