液相烧结工艺制备高钒钢  

Fabrication of a High Vanadium High Speed Steel by Liquid Phase Sintering

作　　者：李志华[1] 肖平安[1] 张霞[1] 卢瑞青[1] 刘海彬[1] 顾景洪 

机构地区：[1]湖南大学材料科学与工程学院,长沙410082

出　　处：《材料研究学报》2016年第9期662-668,共7页Chinese Journal of Materials Research

基　　金：国家自然科学基金资助项目51574119~~

摘　　要：采用气雾化粉末+压制+超固相液相烧结(SLPS)工艺制备钒含量(质量分数)约为10%的高钒钢,研究了烧结工艺对致密化行为、显微组织演变、相构成与分布和力学性能的影响规律。结果表明,烧结温度的影响最全面,保温时间主要影响碳化物的析出量。烧结高钒钢的基体为针状M和少量残余γ,在基体中有VC、复合型碳化钼和碳化铬等碳化物,VC大多呈球形,分布在晶界和晶粒内部。随着烧结温度的提高和保温时间的延长,晶粒和碳化物逐渐粗化,各类碳化物的析出越来越充分,而复合型碳化物的析出对高钒钢的强度和冲击韧性有不利影响。烧结高钒钢具有优秀的综合力学性能:硬度HRC 65-68,冲击韧性高于6 J/cm2,抗弯强度高于1800 MPa。High speed steels with high V content （HVHSS, 10 mass % of V） were fabricated by a pro- cess of pressing plus super solid-liquid phase sintering （SLPS） with atomized alloy powder as raw materi- al. The effect of sintering parameters such as sintering temperature and holding time on densification, mi- crostructure evolution as well as mechanical properties were systematically investigated, and the compo- sition, morphology and distribution of the phases existed in the alloy were carefully analyzed. The results show that sintering temperature is the most important parameter affecting the performance of the sin- tered alloys, however holding time shows the main effect on the precipitation and evolution of carbides. The matrix of the as prepared HVHSS consists of acicular martensite and retained austensite, and there are three types of carbides, i.e. VC, complex molybdenum carbide and complex chromium carbide. Small spherical VC particles mainly distribute in the grains and along their boundaries. As sintering temperature and holding time increased, not only grains and carbides gradually coarsened but also more and more carbides precipitated. However, the precipitation of complex carbides deteriorates the alloy＇ s strength and toughness due to their poor morphology which cause serious stress concentration or forming carbide network along grain boundaries. The HVHSS possess high performance, such as hardness HRC 65-68, impact toughness and bending strength over 6 J/cm2 and 1800 MPa respectively.

关 键 词：金属材料 高钒钢 超固相液相烧结 力学性能 碳化物 

分 类 号：TG142[一般工业技术—材料科学与工程]