退火温度对含铌微合金高强钢力学性能的影响

Effect of Annealing Temperature on Mechanical Properties of Niobium-containing Microalloyed High Strength Steel

模拟含铌微合金高强钢的卷曲过程并在不同温度下进行退火处理试验。检测不同退火温度下试验钢的力学性能,结合OM、EBSD和TEM方法,研究退火温度对试验钢微观组织和力学性能的影响。结果表明,随着退火温度的升高,铁素体晶粒长大,铌-碳析出相粗化并发生溶解,试验钢断后伸长率逐渐增加。当退火温度由780℃升高到800℃时,试验钢的屈服强度和抗拉强度大幅度降低,而退火温度由800℃增加到820℃时,试验钢的屈服强度和抗拉强度下降幅度较小。

The crimp process of high strength steel containing niobium microalloy was simulated and the steel was annealed at different temperatures. The mechanical properties of the steel were tested at different annealing temperatures.Combined with OM, EBSD and TEM methods, the effects of annealing temperature on microstructure and mechanical properties of test steel were studied. The results show that, with the increase of annealing temperature, ferritic grains grow up,the niobium carbon precipitate phase coarsens and dissolves, and the extension rate of the test steel after break increases gradually. When the annealing temperature rises from 780 ℃ to 800 ℃, the yield strength and tensile strength of the test steel are greatly reduced. When the annealing temperature increases from 800 ℃ to 820 ℃, the yield strength and tensile strength of the test steel decrease a little.