超超临界火电站用COST-FB2转子钢控氮工艺研究  

Nitrogen Control Process of COST-FB2 Rotor Steel for Ultra-supercritical Thermal Power Station

作　　者：彭雷朕 姜周华 耿鑫 李晓凯 PENG Lei-zhen;JIANG Zhou-hua;GENG Xin;LI Xiao-kai(School of Metallurgy,Northeastern University,Shenyang 110819,China)

机构地区：[1]东北大学冶金学院,辽宁沈阳110819

出　　处：《东北大学学报（自然科学版）》2020年第4期505-509,527,共6页Journal of Northeastern University(Natural Science)

基　　金：国家重点研发计划项目(2016YFB0300203).

摘　　要：利用30 kg真空感应炉进行不同氮分压和渗氮时间条件下的气相渗氮实验和热力学计算,研究COST-FB2钢的气相渗氮工艺.使用ARL4460直读光谱仪、TC-500气体分析仪、HIR-944B红外分析仪等对冶炼铸锭中部成分进行分析.结果表明:渗氮压力≤20 kPa时,计算值和实验值吻合较好;气相渗氮是一级反应,渗氮时间为15 min时,钢中氮含量达到平衡值;氮分压为1.5~6 kPa时,COST-FB2钢中氮的质量分数可控制在0.015%~0.03%;为了避免浇铸过程中铸锭内部形成气孔缺陷,宜采用加压浇铸,压力至少为20 kPa;为避免钢中大颗粒BN的形成,钢中氮的质量分数应控制在0.015%~0.02%,冶炼时,氮分压应控制为1.5~3 kPa.The gas phase nitriding process of COST-FB2 steel was studied by conducting the gas phase nitriding experiment and thermodynamic calculation under different nitrogen partial pressure and nitriding time in a 30 kg vacuum induction furnace.The optical emission spectrometer ARL 4460,gas analyzer of TC-500 and infrared analyzer HIR-944B were used to analyze the content in the middle part of ingot sample.The results showed that the calculated data is in a good agreement with the experimental one when the nitriding pressure is≤20 kPa.Since gas phase nitriding is a first-order reaction,the nitrogen content in the tested steel can reach the equilibrium value with the nitriding time of 15 min.When the partial pressure of nitrogen is 1.5~6 kPa,the mass fraction of nitrogen in COST-FB2 steel can be controlled between 0.015%~0.03%.In order to avoid the formation of porosity defects inside the ingot during casting,pressure casting should be preferred to use with a pressure of at least 20 kPa.Moreover,the mass fraction of nitrogen in steel should be controlled between 0.015%~0.02%and the nitrogen partial pressure should be 1.5~3 kPa during smelting so that the formation of large particle BN in the tested steel can be avoided.

关 键 词：COST-FB2 氮的合金化 氮分压 Factsage方法 氮化硼(BN) 

分 类 号：TF02[冶金工程—冶金物理化学]