冷却速度和Ni对铸造Fe-TiB2钢陶瓷颗粒析出规律的影响  

Effects of Cooling Rate and Ni on Precipitation Law of Ceramic Particles in Cast Fe-TiB2 Steel

作　　者：谢镐 石增敏 周起云 戴雷 XIE Hao;SHI Zengmin;ZHOU Qiyun;DAI Lei(College of Materials and Chemistry,China Three Gorges University,Yichang 443002,China;Hubei Key Laboratory of Hydroelectric Machinery Design&Maintenance,China Three Gorges University,Yichang 443002,China)

机构地区：[1]三峡大学材料与化工学院,湖北宜昌443002 [2]三峡大学水电机械设备设计与维护湖北省重点实验室,湖北宜昌443002

出　　处：《热加工工艺》2022年第19期20-25,共6页Hot Working Technology

基　　金：湖北省技术创新专项(重大项目)(2017AAA113);国家自然科学基金项目(51201093);国家重点基础研究发展计划项目(2010CB630802)。

摘　　要：采用真空电弧熔炼工艺制备了Fe-TiB2颗粒增强钢,研究了亚快速冷却速度和Ni对TiB颗粒析出规律的影响。结果表明:Fe-TiB2钢的铸造组织均为α-Fe和TiB两相组织。在亚快速冷却铸造条件下,TiB相不能完全析出。初生TiB陶瓷相为粗大的带尖角块状颗粒,共晶TiB陶瓷相为细小、不规则条状形貌。初生TiB陶瓷相体积分数随冷却速度的降低而降低,共晶TiB陶瓷相的体积分数随之增加。Fe-Ti-B三元系钢铸造过程中存在δ-Fe铁素体和TiB初生相的先共晶相变过程。Fe-Ni-Ti-B四元系钢中的Ni则抑制了初生TiB相及δ-Fe铁素体的高温析出,促进了γ-Fe和TiB共晶转变,因而显著改变了室温铸造组织的组成和TiB陶瓷颗粒增强相的分布特征。The Fe-TiBparticle-reinforced steel was prepared by vacuum arc melting process. The effects of sub-rapid cooling rate and Ni on the precipitation regularity of TiBparticles were studied. The results show that the casting microstructure of Fe-TiBsteel consists of two phases of α-Fe and TiB. Under sub-rapid cooling casting conditions, the TiBphase cannot be completely precipitated. The primary TiBceramic phase is coarse block-like particles with sharp corners, and the eutectic TiBceramic phase is fine and irregular strip-like morphology. The volume fraction of primary TiBceramic phase decreases with the decrease of cooling rate, while the volume fraction of eutectic TiBceramic phase increases. During the casting process of Fe-Ti-B ternary steel, there is a pro-eutectic transformation process of δ-Fe ferrite and TiBprimary phase.Ni in Fe-Ni-Ti-B quaternary steel inhibits the high temperature precipitation of primary TiBphase and δ-Fe ferrite, and promotes the eutectic transformation of γ-Fe and TiB, thus significantly changing the room temperature casting microstructure composition and distribution characteristics of the reinforcing phase TiBceramic particles.

关 键 词：Fe-TiB2钢 颗粒增强 析出 相转变 铸造 

分 类 号：TG244.3[金属学及工艺—铸造] TG142.1[一般工业技术—材料科学与工程]