摘要
P91耐热钢焊接用芯线中Al会与N结合生成AlN,造成强化析出相(Nb、V)(C、N)的减少,使钢的持久强度和抗蠕变性能降低。以真空熔炼加电渣重熔技术研究P91耐热钢焊接用芯线中的Al含量,在真空条件下通过热力学计算得出真空熔炼时坩埚中氧化铝被碳还原与真空度的关系,当真空度为2Pa时,Al含量最大达到0.0085%。因此,必须合理使用耐火材料刚玉粉才能使Al含量满足不超过0.0010%的要求。电渣采用渣系CaF2-MgO冶炼的电渣锭顶部和底部Al含量分别为0.0007%、0.0008%,实现了电渣过程不增Al。电渣锭金相组织为马氏体,有少量灰色夹杂物,夹杂物为氧化物复合相(Fe、Mn、Cr)xOy,未发现铝及铝的氧化物存在。
In P91 welding core AlN is formed by the combination of Al and N,resulting in a decrease in the number of precipitated phases（Nb、V）（C、N）,reducing the persistent strength and creep resistance of the material.In this paper,vacuum smelting and electroslag remelting technology is used to study the aluminum content in P91 welding core,the thermodynamic calculation shows that the relationship between carbon reduction of alumina and vacuum degree during vacuum melting,when the vacuum degree is 2 Pa,the maximum aluminum content can reach 0.0085%.Through reasonable use of corundum powder to make the alumina content to meet the requirements of less than 0.001%.Electroslag remelting with CaF2：MgO = 80：20,the top and bottom aluminum contents are 0.0007% and 0.0008% respectively,to achieve the electroslag process does not increase aluminum.The microstructure of electroslag ingot is martensite and a small amount of gray inclusions,the inclusions are oxide composite phase（Fe,Mn,Cr）xOy,microscopic analysis showed that there was no aluminum and alumina inclusions in the tissue.
作者
金一标
李亚军
胡学峰
张庭志
JIN Yibiao LI Yajun HU Xuefeng ZHANG Tingzhi(Sichuan Atlantic ShenYuan Special Material Technology Co., Ltd., Zigong 643000, Sichuan, China Atlantic China Welding Consumables, INC., Zigong 643000, Sichuan, China)
出处
《四川冶金》
CAS
2017年第5期24-28,共5页
Sichuan Metallurgy
关键词
析出强化
控铝
真空熔炼
电渣重熔
precipitation strength, aluminum control, vacuum melting, electroslag remelting
