SAF2906双相不锈钢超塑性研究

通过恒温拉伸机对固溶处理与冷轧加工后的SAF2906双相不锈钢进行恒温拉伸试验，分析其在不同条件下超塑性伸长率的变化。利用扫描电镜与透射电镜对其进行内部组织观察，了解其两相比例的变化情况。试验结果表明，SAF2906双相不锈钢中铁素体相(δ相)与奥氏体相(γ相)的两相体积比随固溶温度的变化而改变，随着固溶温度的升高铁素体比例不断上升，其中当铁素体与奥氏体的两相体积比接近1∶1的情况下，SAF2906双相不锈钢展现出良好的超塑性性能；在机械加工方面可以通过提高冷轧压下量的方法提高SAF2906双相不锈钢的超塑伸长率，试验中试样的伸长率随着冷轧变形量的提高而明显增大，当固溶温度为1 100 ℃，冷轧压下量为85%时，变形温度为960 ℃，应变速率为1×103 s1的条件下，SAF2906双相不锈钢伸长率为1 430%。

Study on Superplasticity of SAF2906 Duplex Stainless Steel

SAF2906 duplex stainless steel is tested on an isothermal tensile machine for studying its plastic elongation after be treated by different solutions and cold rolled. The microstructures are observed by scanning electron microscopy (SEM) and transmission electron microscopy(TEM). The results indicate that the volume ratio of δ-ferrite phase to γ-austenite phase varies with the solution temperature, and the SAF2906 duplex stainless steel had an excellent superplastic forming property with the closed 1∶1 volume ratio. The elongation of SAF2906 duplex stainless steel could be enhanced by increasing rolling reduction rate, and the elongation of the specimen solution-treated at 1 100 ℃, rolled on 85% reached to1 430% at a deformation temperature of 960 ℃ and a strain rate of 1×103 s1