加热温度对钛铌微合金钢中未溶颗粒形貌和成分的影响

Effect of Heating Temperature on Morphology and Composition of Undissolved Particles in High Strength Steel Containing Ti-Nb

采用SEM、TEM及EDS分析技术,研究了含钛、铌等多种微合金元素的高强钢中碳氮化物的溶解行为。结果表明:保温30 min,加热温度低于1200℃时,钢中未溶颗粒主要是球形和椭球形;加热温度为1250℃时,未溶颗粒以圆角的长形及方形为主。上述颗粒均为含铌和钛的复合碳氮化物。随加热温度的升高,球形、椭球形颗粒减少,长形及方形颗粒增多。圆角的长形及方形颗粒中Ti/Nb原子比显著高于球形和椭球形颗粒。加热温度为1 250℃时,长形及方形颗粒中的Ti/Nb原子比约为97/3。

The dissolution behaviors of carbonitride in high strength steel bearing Ti Nb were investigated by scanning electron microscope （SEM）, transmission electron microscope （TEM） and electron energy spectrum （EDS） technique. The experimental results have shown that the undissolved particles were mainly complex carbo-nitride containing Nb and Ti with a spherical or ellipsoidal shape when the steel was soaked at a given temperature lower than 1 200℃ for 30 min. A small amount of the cuboid undissolved particles was observed in the steel when heated at 1 250 ℃ for 30 min with minute quantity of irregularity morphologyic particles. The above particles were also complex particles containing Ti and Nb. With the increase of soaking temperature, the number of spherical and ellipsoidal particles decreases and the number of cuboid undissolved particles increases. The Ti/Nb atomic ratio of the former is much higher than that of the latter. The Ti/Nb atomic ratio of the cuboid particles is about 97/3.