Effect of Grain Boundary Character Distribution on the Impact Toughness of 410NiMo Weld Metal

Grain boundary character distributions in 410NiMo weld metal were studied in the as-welded, first-stage, and second-stage postweld heat treatment (PWHT) conditions, and these were correlated with the Charpy-V impact toughness values of the material. The high impact toughness values in the weld metal in the as-welded and first-stage PWHT conditions compared to that in the second-stage condition are attributed to the higher fraction of low-energy I pound boundaries. A higher volume fraction of retained austenite and coarser martensite after second-stage PWHT accompanied by the formation of the ideal cube component in the 2-hour heat-treated specimen led to a reduction in the toughness value. A subsequent increase in the PWHT duration at 873 K (600 A degrees C) enhanced the formation of {111}aOE (c) 112 >, which impedes the adverse effect of the cubic component, resulting in an increase in the impact toughness. In addition to this, grain refinement during 4-hour PWHT in the second stage also increased the toughness of the weld metal

The 'lost child' as figure of trauma and recovery in early post-war cinema: Fred Zinnemann's The Search (1948) and Natan Gross's Unzere Kinder (1948)

The article examines the figure of the ‘lost child’ in feature films of the immediate post-war period. The figure’s enormous symbolic value as innocent victim and future generation, granted the ‘lost child’ a key position in post-war discourse, including films which tried to grapple with the moral and physical destruction of the continent after 1945. National film industries, particularly of the perpetrator nation, employed the ‘lost child’ for genre stories in which the post-war chaos is being mastered and a new, masculine national self is re-built. However, films made by victim groups outside a national context rely on the ‘lost child’ to broach the destruction of their identity by war and persecution. Analysing two films, Fred Zinnemann’s The Search (1948) and Nata Gross’s Unzere Kinder (1948), I argue that they use the child figure to deal with traumatization and make it part of the reconstruction of communal intergenerational relations. This does not result in stories of masculine mastery but in narratives that incorporate moments of trauma process emerging around destroyed mother-child relations. The films, encoding traumatization in film language, develop a rich cinematic language along questions of identity and form a first instance of posttraumatic cinema

Une méthode améliorée de mesure de la polarisabilité des atomes libres à l'aide du microscope électronique de champ

The trajectories of neutral atoms are curved near the tip of a field electron microscope, due to their polarization in the inhomogeneous electric field. This phenomenon has permitted a rough measurement of the polarizability of atoms (Drechsler an Müller). We have now generalized the theory and modified the method of measurement in order to improve the precision and to simplify the application. It is found that the trajectories depend on one parameter which includes the polarizability (α), the mass, the initial velocity of the particle and the electric field strength at the tip apex. α can be determined if one measures the two times which are necessary to obtain the same degree of coverage on one face of the tip by adsorption of the beam atoms with and without field. The degree of coverage is monitored by measuring the field electron current emitted from this face. As an example, the method is used to measure the polarizability of Pb ; the result is : α = 19,5 ± 6 Å3 which is in agreement with theoretical estimations.Les trajectoires des atomes neutres sont courbées près de la pointe d'un microscope électronique de champ, à cause de leur polarisation par le champ électrique inhomogène. Ce phénomène a permis de déterminer la polarisabilité α des atomes du jet (Drechsler et Müller). Nous avons généralisé la théorie et modifié la méthode de mesure pour améliorer la précision et simplifier l'utilisation. On trouve que la forme des trajectoires dépend uniquement d'un paramètre qui inclut la polarisabilité (α) la masse, la vitesse initiale et le champ électrique au sommet de la pointe. On peut déterminer la polarisabilité si l'on mesure les deux temps nécessaires pour déposer sur une face de la pointe, à l'aide d'un jet de flux constant, le même degré de recouvrement avec et sans champ. La méthode a été appliquée à l'atome de plomb ; on a obtenu : α = 19,5 ± 6 Å3, ce qui est en accord avec les estimations théoriques

Role of Grain Boundary Character Distribution on Tensile Properties of 304L Stainless Steel

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