• CN:11-2187/TH
  • ISSN:0577-6686

›› 1988, Vol. 24 ›› Issue (1): 50-57.

• 论文 • 上一篇    下一篇

双相钢中的Bauschinger效应和背应力

马呜图;孙珍宝   

  1. 重庆重型汽车研究所;北京钢研究总院
  • 发布日期:1988-01-01

BAUSCHINGER EFFECT AND BACK STRESS IN DUAL FHASE STEEL

Ma Mingtu Sun Zinbao   

  1. 重庆重型汽车研究所 Center Iron and Steel Research Institute
  • Published:1988-01-01

摘要: 本文研究了Mn-V热处理双相钢中的Bauschinger效应和背应力。结果表明:Mn-V热处理双相钢中存在有Bauschinger效应和永久软化,在预应变引入基体中的位错是可动的条件下,背应力帮助位错运动,导致反向流变时屈服应力下降和反向流变曲线圆化,产生Bauschinger效应。对双相钢中的背应力与显微组织之间的关系测定与计算表明:双相钢的背应力硬化机制与弥散硬化合金类同,时效可以消除双相钢中的Bauschinger效应,但不改变背应力大小,而反向流变可使Bauschinger效应和背应力同时下降或消除。

Abstract: The Bauschinger effect and back stress in Mn-V heat treatment dual phass steel have been investigated. The influence of reverse flow and aging at 175℃ on the Bauschinger effect and back stress and the relation between back stress and microstructure parameters have been measured. The results show that there are Bauschinger effect and permanent softening in the dual phase steel studied. The Bauschinger effect is mainly related to the mobile dislocations and dislocation configulations with directionality in their resistance to motion and the back stress in the matrice due to prestrain. Only under the condition of dislocation being mobile (for example dislocation being not locked by Cottrell atmosphere) the back stress can facilitate dislocation to reverse motion and resulting in decreasing of yield stress during the reverse flow and rounding off of reverse flow cure as well as producing Bauschinger effect. The relation between the back stress and microstructure parameters of dual phase steel were calculated by using of back stress hardening model evolved by Brown and Stobbs for describing back stress hardening mechanism. The calculated results have good cerelation with measured results. It shows that the back stress hardening mechanism in dual phase steel ,bears analogy with that in the dispersion hardening alloy. The aging at 175℃ can dispel Bauschinger effect but does not change the value of back stress in dual phase steel. However, the reverse flow can simultanuously decrease or dispel Bauschinger effect and back stress in dual phase steel.