摘要
在Fe-V-Nb-Mo-Cr-C体系中,通过添加不同量的Nb,以制备不同Nb/V摩尔比的铁基复合材料。用扫描电镜、X射线衍射仪对该复合材料的微观结构和相构成进行分析。结果表明,在粉末冶金过程中,原位生成了(V,Nb)C硬质相,且随Nb/V摩尔比的增加,(V,Nb)C的晶格常数近似呈线性增加。随Nb/V摩尔比的提高,硬质相颗粒的尺寸逐步减小至2μm。结果表明:抗弯强度随Nb/V摩尔比的增加而升高,在Nb/V摩尔比为0.4时,出现抗弯强度下降的拐点,此时复合材料试样抗弯强度最高(达到1300 MPa):Nb/V摩尔比为0.5的试样由于具有最高的硬度和最小的碳化物颗粒尺寸,硬度为85.5HRA,其耐磨性最好,是高铬铸铁的5倍。
A series of iron-base composites with various Nb/V molar ratios were fabricated by the addition of different amount of Nb to Fe-V-Nb-Mo-Cr-C system. The microstructure and phase composition of the prepared composite were analyzed by SEM and XRD. The results indicate that the hard（V,Nb）C phase appears in in-situ during the process of powder metallurgy. Furthermore,the lattice constant of（V,Nb）C phase increases approximatively linearly with augment of Nb/V molar ratio,and the particle size of hard phase gradually decreases to 2μm. The bending strength test confirms that it would steadily increase until the Nb/V molar ratio is not more than 0.4. The maximum bending strength of those composite,1300 MPa would be obtained when Nb/V molar ratio is 0.4. However,the break point of the decrease of bending strength would appear after it is larger than 0.4. Abrasion test demonstrates that the composite with Nb/V molar ratio of 0.5 possesses the best abrasion resistance and the hardness value is 85.5HRA,which is five times higher than that of high-chromium iron,as a result of smallest carbide particles size and highest hardness.
出处
《热加工工艺》
CSCD
北大核心
2015年第18期118-122,共5页
Hot Working Technology
基金
四川省科技计划基金项目资助(2010JY0076)
