变形温度对超级双相不锈钢S32750性能的影响

Effect of deformation temperature on properties of super duplex stainless steel S32750

超级双相不锈钢高温塑性变形过程中由于铁素体和奥氏体两相变形机制的不同,使得在成型过程中极易产生裂纹从而导致产品报废。本试验根据相关国家标准,通过无损检测、拉伸试验、显微硬度试验并结合显微组织分析对超级双相不锈钢S32750成形工艺中的温度参数进行研究。结果显示：在选定的变形量下,随着温度的升高,铁素体数量显著增加,铁素体相的强化作用将会大于晶粒长大的负面影响,从而使得试样抗拉强度随着温度的升高而逐渐增加,伸长率达到峰值32%后开始降低。因此最佳的高温塑性变形温度为1200℃,并对此钢种的锻造工艺优化提出了相关建议。

Due to the different deformation mechanisms of ferrite and austenite in the process of high temperature plastic deformation of super duplex stainless steel,cracks are easy to occur in the process of forming,resulting in product scrap. According to the relevant national standards,the temperature parameters in the super duplex stainless steel S32750 molding process were studied by nondestructive testing,tensile test,microhardness test and microstructure analysis. The results show that under the selected deformation,with the increase of temperature,the amount of ferrite increases significantly,and the strengthening effect of the ferrite phase can be greater than the negative influence of the grain growth. Thus,the tensile strength of the sample increases with the increase of temperature,and the elongation decreases after reaching to its peak value of 32%. Therefore,the optimization temperature at the condition of high temperature plastic deformation is 1200 ℃,and some relevant suggestions for the optimization of the forging process of this steel are proposed.