低C高Si高Mn合金钢表面氧化皮剥壳性能分析

采用SEM、EPMA及拉伸试验等手段研究了影响低C高Si高Mn合金表面氧化皮机械剥壳性能的因素,并测试了自然放置对氧化皮机械剥壳性能的影响。结果表明,氧化皮/基体界面的粗糙度大及富Si层与基体结合紧密是导致该合金表面氧化皮难脱落的主要原因。Si元素在界面处的聚集导致热轧后的盘条表面不均匀氧化,从而加大了界面的粗糙度。自然放置可促使表面氧化皮包括富Si层的碎化、剥离,有利于改善盘条氧化皮的机械剥壳性能。

Effect of Si content on interfacial reaction and properties between solid steel and liquid aluminum

The effect of Si content on the microstructures and growth kinetics of intermetallic compounds(IMCs)formed during the initial interfacial reaction(<10 s)between solid steel and liquid aluminum was investigated by a thermophysical simulation method.The influence of Si addition on interfacial mechanical properties was revealed by a high-frequency induction brazing.The results showed that IMCs layers mainly consisted ofη-Fe_(2)Al_(5)andθ-Fe_(4)Al_(13).The addition of Si reduced the thickness of the IMCs layer.The growth of theηphase was governed by the diffusion process when adding 2 wt.%Si to the aluminum melt.When 5 wt.%or 8 wt.%Si was added to aluminum,the growth was governed by both the diffusion process and interfacial reaction,and ternary phaseτ1/τ9-(Al,Si)_(5)Fe_(3)was formed in theηphase.The apparent activation energies of theηphase decreased gradually with increasing Si content.The joint with pure aluminum metal had the highest tensile strength and impact energy.

含硅、磷钢在2%残氧气氛下的高温氧化行为研究

通过热重试验测量了Si、P含量不同的3种钢在2%残氧气氛下的氧化动力学;研究了Si、P含量对不同钢种氧化的影响。通过高温氧化动力学试验,发现3种钢的氧化动力学符合抛物线规律,计算得到3种钢的氧化激活能分别为90.04、91.87、239.95kJ/mol。在800~1 100℃的氧化过程中,氧化速率随着S、P含量的增加而减小;当温度上升至1 100℃以上,氧化速率随着Si含量的增加而增大,当钢中Si的质量分数超过0.67%时,影响尤其显著。