9%Ni钢中沉淀奥氏体的形成过程及其在深冷下的表现

研究了9%Ni钢在两相区温度保温时沉淀奥氏体的析出过程及其对低温冲击韧性的影响。结果表明:在两相区保温由于C,N及Ni的重新分布,形成富Ni,Mn及C,N的奥氏体富集区及相对纯化的铁素体富集区,两者呈深浅相间的条带状组织。中温转变的奥氏体冷却到室温时部分转变成马氏体。这种第二代马氏体与奥氏体高度细化,并交织在一起形成复杂的组织。而奥氏体中高度富集C,N及Ni,它在极低温度下仍很稳定。低温冲击断口的撕裂岭都是沉淀奥氏体密集的,它们沿撕裂方向拉长。说明细碎的马氏体与奥氏体交织的组织既保持一定的强度也提高了低温韧性,这同回转奥氏体吸收杂质纯化基体密切相关。

一种新的马氏体形态

本文对Fe 29.37Ni-0.34C合金中的马氏体形态和亚结构进行了研究,试样经过两次分级冷却后,通过彩色金相和薄膜透射电镜研究表明,在不同的温度下,存在着透镜片状、中突片状和薄片状三种不同形态的马氏体。中突片状马氏体具有强烈的中间突起的表面浮突,对称双孪晶或半孪晶半位错的亚结构等特征,这种马氏体的形成可用应力诱发复生的机制来描述。

Morphology and Effect of Pre-deformation on Martensites by Colored Metaliography August 24,1990

The colored metallography was used to inves-tigate the morphology of martensite in Fe-Ni-C al-loys.By compression deformation martensite trans-forms from lenticular to thin-plate.It is provedthat the bended and broken martensites are inher-ent from compressive predeformation of austenite.

铸铁中石墨形态及形成机理的最新探讨

运用经典动力学和缩聚理论的基本观点对铸铁中石墨形态及形成机理进行了分析研究。结果表明：浇注后的铁水内部由于温度降低而析出的石墨融乳液滴的缩聚与扩散能力，金属液体的粘度及其内部各处由于存在温度梯度而产生的温差点电势场的变化率，导磁性元素硅的晶体四块的自旋速率，其它合金元素的相互影响乃是决定铸铁中石墨形态的关键因素。同时认为，矽晶体团块自旋动量的最大值只有在温差点电势场湮灭的瞬间取得。

Effect of Compressive Deformation on Lenticular and Thin Plate Martensitic Transformations

The effect of compressive deformation testedabove the M_s temperature on the martensitemorphology in Fe-Ni-C alloys has been studied.Inthe Fe-30Ni-0.12C alloy,the M_s temperature is-50℃ The cylindrical specimens werecompressively deformed at -40℃.The strain rateswere 10,20,30 and 40%.X-ray analysis andmetallographic examination showed that nostrain-induced martensite was found.After quench-ing to -53℃,some thin plates and unusualmorphologies of lenticular martensites with bentand/or broken mid-ribs were observed.In theFe-30Ni-0.34C alloy,the M_s temperature is-120℃.Compressive deformation with differentstrain rates were carried out at room temperature.After quenching to the liquid nitrogen temperature,some bent thin plate matensites(unbroken)occur-red.The transformed twins in bent plate were alsobent and nearly parallel to the γ-α’interfaces.Orientation relationship between austenite and bentmartensite has been examined by means of trans-mission electron microscope.It was proved thatthese unusual morphologies are inherent in thecompressive pre-deformed austenite.

悠悠往事 碌碌生平——印象中的师昌绪

师昌绪——大小也算是个名人,但走在大街的人群里也就是个不起眼的小老头,这才是真实的师昌绪（图1）。有一次师昌绪路过一个大型电子仪器专卖店想进去看看,不料走到门前就被门卫拦住,门卫很严肃地对他说：＂你干什么？＂他回答：＂想进去看看。＂门卫上下打量着他说道：＂你知道吗,这不是一般的购物中心,这是卖高级电子设备的……＂,话音未了,从楼里面走出来一位衣冠整洁的年轻人,打着招呼向他走来,招呼道：＂师老,您也来光顾电子商城啊……＂,此时,那个神气活现的门卫顿时惊呆了!一场闹剧就此告终。