高硼抗磨不锈钢的研究和应用

Investigation and Application of High Boron Abrasive Wear Resistant Stainless Steel

在普通奥氏体不锈钢中加入超过1.0%（质量分数）的硼,铸态下获得了奥氏体基体上分布着高硬度硼化物的复合组织。借助光学显微镜、扫描电镜、电子探针、能谱分析、X射线衍射和维氏硬度测量等手段,研究了硼化物的组成以及合金元素在硼化物和金属基体中的分布情况,并研究了高硼抗磨不锈钢高温固溶后的显微组织和性能的变化情况。结果发现硼化物的主要组成是Fe、Cr、B,另外还含有少量的Ni、Mn、C,Si基本不溶于硼化物中,硼化物硬度超过HV1500。经高温固溶处理后,硼化物不分解,但出现局部溶解现象,使奥氏体中B的固溶度增加,促使高硼抗磨不锈钢硬度提高8.54%。高硼抗磨不锈钢用于制造锌液输送管道,使用寿命比普通不锈钢提高1.5-1.8倍。

Adding more than 1.0% （mass fraction） B in the common austenitic stainless steel,a composite structure of borides and austenite was obtained. The hardness and compositions of borides and the distribution of elements over the metallic matrix and borides were studied by means of the X-ray diffraction （XRD） , the electron probe microanalyzer （ EP- MA）, the optical microscopy （OM）, the scanning electron microscopy （SEM） and the energy dispersive X-ray spectrometry （EDS） and Vickers microhardness measurement. Metallographic observations were made on samples etched in a mixture of 5 mL HC1,45 mL 4% Picral and 50 mL 5% natal. The changes of microstructure and property of high boron abrasive wear resistant stainless steel after solution treatment at high temperature of 1 050℃ were investigated. The results show that the main compositions of borides are Fe, Cr and B, and there is a small amount of Ni, Mn and C in the borides. Silicon is insoluble in the carbides. The hardness of borides is over HV 1 500. After solution treatment at high temperature of 1 050 ℃, the borides do not decompose, but part of borides dissolves into the matrix, which increases the solubility of boron element in the austenitic matrix and promotes the hardness of stainless steel by 8. 54%. The life of transfer pipe of zinc liquid made from the high boron abrasive wear resistant stainless steel is 1.5 - 1.8 times longer than that of common stainless steel pipe.