中文摘要：

9Cr18 钢的一个 thixoforging 过程在设计安装被进行，并且一种多直径部件被制作。solid-/liquid-phase 流动行为上的形成的温度和紧张率的效果被讨论。结果证明 9Cr18 钢的功能的坡度性质能在 thixoforging 以后被获得。沿着光线的方向的微观结构的变化能被获得。稳固的奥氏体在快冷却以后被保留，并且液体电影在 alloying 元素充实在外面被渗出形成树突皮肤层。当温度增加了，更熔融的液体在 thixoforging 期间形成了。当免费液体隧道被形成，异构的流动现象被激活。固体和液体阶段的宏分离为功能的坡度性质的形成是批评的。超过 1300 ?獬睥敨敲?敐桲灡?瑩?瑳潲杮獥?潣瑮楲畢楴湯椠?硥汰楡楮杮栠睯愠朠潲灵漠?潦歬?慨?敢湥愠獳浥汢摥戠?桴?湥?景琠敨ㄠ?猰眠潨?晡整?潗汲?慗???潷汵?慭敫映汯?畭楳?桴?浩潰瑲湡?慰瑲漠?流牥捩湡瀠灯汵牡挠汵畴敲椠?敲慭湩?潴慤?圠瑩?潴慤獹愠捣汯摡獥映牯?慥?敂汬?圠潯祤?瑵牨敩愠摮倠瑥?敓来牥?湡?潂?祄慬?敧瑴湩?桴???丠扯汥倠楲敺映牯?瑩牥瑡牵??桯湥映汩獬椠?桴?瑳牯?桷湥映汯?畭楳?慷?敳湥愠??畣楲獯瑩?慲桴牥琠慨??楶慴?氠癩湩?畭楳慣?潦浲?效搠獥牣扩獥栠睯琠楨?慷??牰橯'?景愠栠？？

英文摘要：

A thixoforging process of the 9Cr18 steel was conducted in a designed setup, and a kind of multi-diameter component was fabricated. The effects of the forming temperature and the strain rate on the solid-/liquid-phase flow behavior were discussed. The results showed that functional gradient properties of the 9Cr18 steel could be obtained after thixoforging. Changes of microstructure along radial direction could be obtained. Solid austenite was retained after fast cooling, and the liquid film enriched in alloying elements was extruded outside to form a dendrite skin layer. As temperature increased, more molten liquid formed during thixoforging. A heterogeneous flow phenomenon was activated as free liquid channels were formed. The macro-separation of solid and liquid phases was critical for the formation of functional gradient properties. Above 1300 ℃, full dendrite skin layer could be formed. The strain rate affected the thixotropic property via influencing the deformation time of thixoforging. In the presence of lower strain rates, there was more time for the flow of liquid metal, which was the key to the extension of the thixotropic stage. High temperatures and low strain rates contributed to the formation of full skin layer for the designed specimen. The average thickness of skin layer for current specimen could be over 1000 ktm when thixoforged at 1340 ℃ and under a strain rate of 0.02 s^-1.