一种新型的含镍耐蚀高硅铁基合金

A new type of corrosion resistance high silicon iron-base alloy with Ni

借助光学显微镜、扫描电镜、能谱分析、X衍射分析和力学性能检测设备及腐蚀性能检测仪器等手段,结合奥氏体不锈钢的设计思路以及Fe-Ni-Si和Fe-Mn-Si三元相图,分析了普通高硅铁基合金的性能和组织,设计并研究了含镍或锰奥氏体高硅铁基合金的组织、力学性能和耐蚀性能.结果表明:普通高硅铁基合金的基体均为铁素体,主要是长程有序的Fe3Si相,这种相有低温脆性现象同时是合金产生硅脆的根本原因.在合金中加入18%的镍,能使合金中出现奥氏体相,其冲击韧性达到5·52J·cm-2,比普通高硅铁基合金提高7倍以上,腐蚀率和普通高硅铁基合金相当.

An austenitic high silicon iron-base alloy with Ni or Mn was devised based on the study on the mechanical properties and microstructure of a general high silicon iron-base alloy. The new austenitic high silicon iron-base alloy with Ni or Mn was designed by means of austenitic stainless steel and the three-element phase graph of Fe-Ni-Si or Fe-Mn-Si. The microstructure, mechanical properties and corrosion resistance of the alloy were investigated by optical microscopy, scanning electron microscopy （SEM）, X-ray diffraction （XRD）, test equipment of mechanical properties, and test instrument of corrosion. The results show that the base structure of a general high silicon iron-base alloy is high silicon ferrite, which is mainly the long-range ordered Fe3Si. Fe3Si has low-temperature brittleness and is the main reason for silicon brittleness. The addition of 18 % Ni produces austenite and causes an impact toughness up to 5.52 J·cm^-2, which is 7 times higher than a general high silicon iron-base alloy, while the corrosion resistance is equivalent with a general high silicon iron-base alloy.