Ni在穿孔顶头制备和穿孔过程中的作用

Effect by Ni on Piercing Plug as being Prepared and Operated

以20Cr2Ni3成品穿孔顶头和失效穿孔顶头为研究对象,探究Ni在穿孔顶头制备和穿孔过程中的作用。对顶头氧化膜的形貌和成分进行分析。研究发现:具有疏松多孔的两层氧化膜结构的成品穿孔顶头在穿孔后发生失效,其外层氧化膜绝大部分脱落,而内层氧化膜与基体紧密黏合在一起。Ni在顶头制备和穿孔过程中,始终以单质的形式存在于内层氧化膜。分析认为:在高温穿孔过程中,富Ni处的氧化膜结构致密、无裂纹,而贫Ni处出现大裂纹;Ni充当黏结剂的作用,将氧化物紧紧地黏合在一起,起到有效保护顶头的作用。

Taking the 20Cr2Ni3 finished piercing plug and the failure piercing plug as the research subjects,the effect by Ni on piereing plug being prepared and operated are studied.And the morphology and chemical composition of the oxide flm of the plug are analyzed.It is identified via the research that when the said porous finished piercing plug with a 2-layer oxide film structure fails afer piercing operation,most part of the outer oxide film peels off,while the inner oxide film sticks onto the basal body tighly;and that during the plug preparation and piercing process,Nitrogen(Ni)always exists in the form of elementary substance in the inner oxide film.The analysis leads to such a conclusion that during the high temperature piercing process,at the Ni enriched location of the oxide film,the strueture is dense and free of any crack,whereas at the Ni-poor location of the oxide film,big cracks are developed;and that in this case Ni acts as some kind of binder,and gets the oxides bond closely,which protects the plug so well.