Al对Fe-18Mn-0.6C钢延迟断裂性能的影响

Effect of Al on delayed fracture resistance of Fe-18Mn-0.6C

利用背散射电子(EBSD),X射线(XRD),扫描电镜(SEM)和慢应变速率拉伸试验(SSRT)等方法,研究Al对Fe-18Mn-0.6C系高锰钢的层错能,力学性能,孪晶数量,延迟断裂性能的影响。结果表明,加入1.5%Al后,通过热力学计算TWIP钢的层错能增加了13 m J·m^(-2),抗拉强度略有降低的趋势,伸长率从原来的39.1%增加到72.3%,EBSD分析表明退火组织中存在退火孪晶,Al可以把晶粒从17.62μm细化到11.21μm,退火后的样品中存在部分退火孪晶,变形后变形孪晶增多,Al的加入可以有效的降低延迟断裂的敏感性。

A high Mn( Fe-18Mn-0. 6C) steel and an Al-added high Mn( Fe-18Mn-0. 6C-1. 5Al) steel were fabricated and their stacking fault energy,microstructure,tensile properties,the number of twins and delayed fracture properties were investigated by means of electron backscatter diffraction( EBSD),scanning electron microscope( SEM),X-ray diffraction and slow strain rate tensile test( SSRT). The stacking fault energy( SFE) is raised with 13 m J·m^(-2),due to adding 1. 5 mass% Al with thermodynamic calculation. The tensile test results indicate that the tensile strength decreases slightly and elongation increases from 39. 1% to 72. 3%. The electron backscatter diffraction( EBSD)observation shows that Al can refine the grains from 17. 62 μm to 11. 21 μm,annealed specimens have some annealing twins,twinning is greatly increased by deformation. Al addition improved the resistance to hydrogen delayed fracture.