渗硼对灰铸铁耐磨性的影响

Effect of Boronizing on the Wear Resistance of Gray Cast Iron

采用商用LSB-Ⅱ型固体粉末渗硼剂对可用作可淬硬凸轮轴的合金灰铸铁进行渗硼处理。渗硼温度分别为850℃、900℃和950℃,保温时间分别为2、4、6和8h。采用Olympus光学显微镜和X射线衍射分析渗硼层厚度和渗层组织。用M200型块环式磨损试验机(淬火加低温回火GCr15钢圆环作为对磨副)研究渗硼和未渗硼(但是进行了淬火和低温回火)合金灰铸铁试样的耐磨性并用S-450型电子探针观察磨损形貌。结果表明,渗硼合金灰铸铁比淬火加低温回火合金灰铸铁的耐磨性更高。

Alloyed gray iron that can be used for a quenchable camshaft has been boronized with solid boron-yielding substances by pack- boronizing method.Commercial LSB-Ⅱ powder has been used as the boronizing agent with treatment temperature of 850℃,900℃ and 950℃,for 2,4,6 and 8h respectively.Thickness,and microstructure of the boride layer have been investigated by an Olympus optical microscopy and X-ray diffractorneter.Sliding wear behavior of the boronized and unboronized cast iron which quenched and tempered at lower temperature were investigated.For this purpose,the specimens have been tested on a type 200 block-on ring test apparatus.GCr15 steel has been used as the moving surface member.Sliding wear tests have been carried out at a fixed load and a fixed sliding speed.The weight loss has been measured and worn surfaces have been examined.Results showed that the boronized alloyed gray iron had higher wear resistance than the alloyed gray iron quenched and tempered ,.t lower temperature