脉冲电流对MS1300超高强钢拉伸变形行为的影响

Effect of pulse current on tensile deformation behavior of MS1300 ultrahigh strength steel

通过电辅助拉伸与等温拉伸实验研究了脉冲电流对MS1300超高强钢拉伸变形行为的影响,并采用扫描电镜观察了MS1300超高强钢的微观组织变化。结果表明,在实验值范围内,随着电流密度的增加,MS1300超高强钢的抗拉强度及断后伸长率均先增大后降低,且断后伸长率均大于未通电等温拉伸时的大小。当脉冲电流密度为6.07 A·mm^(-2)时,MS1300超高强钢抗拉强度与断后伸长率最大。脉冲电流的纯电塑性效应降低了MS1300超高强钢的抗拉强度;但当脉冲电流密度为7.14 A·mm^(-2)时,纯电塑性效应对抗拉强度的影响不明显。当脉冲电流密度为6.07 A·mm^(-2)时,纯电塑性效应提高了MS1300超高强钢的断后伸长率。在脉冲电流作用下,MS1300超高强钢中的马氏体分解,碳化物析出,从而降低了变形抗力,提高了塑性。

The effect of pulse current on tensile deformation behavior of MS1300 ultrahigh strength steel was studied by electrically assisted tension and isothermal tension experiments,and the change of microstructure of MS1300 ultrahigh strength steel was observed by scanning electron microscope.The results show that the tensile strength and elongation after fracture of MS1300 ultrahigh strength steel increase first and then decrease with the increase of current density in the range of experiment values,and the elongation after fracture is higher than that of isothermal tensile without pulse current.When the pulse current density is 6.07 A·mm^(-2),the tensile strength and elongation after fracture of MS1300 ultrahigh strength steel are the largest.The pure electroplastic effect of pulse current reduce the tensile strength of MS1300 ultrahigh strength steel;but when the pulse current density is 7.14 A·mm^(-2),the effect of pure electroplastic effect on tensile strength is not obvious.When the pulse current density is 6.07 A·mm^(-2),the pure electroplastic effect increases the elongation after fracture of MS1300 ultrahigh strength steel.Under the action of pulse current,the martensites in MS1300 ultrahigh strength steel are decomposed and the carbides are precipitated,which reduces the deformation resistance and improves the plasticity.