Characterization of Nonmetallic Inclusions in 18CrNiMo7-6

Metallurgical and Materials Transactions B - The detrimental effect of nonmetallic inclusions (NMIs) in steels on, e.g., fatigue lifetime is well known. In order to increase the durability and...     

Cyclic Deformation Behaviour of Three Austenitic Cast CrMnNi TRIP/TWIP Steels with Various Ni Content

This study presents the cyclic deformation behaviour of three high‐alloyed austenitic cast steels which are characterized by different chemical compositions leading to different austenite stabilities and stacking fault energies. Thus, depending on the chemical composition different deformation mechanisms arise which have a significant influence on the cyclic deformation behaviour and life time relations. The materials were characterized under total‐strain control. The fatigue life relations of Basquin and Manson‐Coffin are applied successfully for all steel variants. The cyclic stress‐strain response is described using the Ramberg‐Osgood relationship. It is shown that the parameters n' and K' depend strongly on the accumulated plastic strain λ_p. The mechanical properties are discussed together with microstructural investigations of deformation structures and martensitic transformations as well as twinning, respectively.     

Comparison of the Stress Intensity Factor of Load-Carrying Cruciform Welded Joints with Different Geometries

The investigation of fatigue strength needs an accurate solution and reliable values of the stress intensity factor (SIF). In this study, SIF of load-carrying cruciform welded joints has been evaluated using finite element method (FEM), and compared with the available solutions from literature. Load-carrying cruciform welded joints with isosceles triangles and non-isosceles triangle fillet weld shapes were considered and have been analyzed by the FEM-based simulator FRANC2D program. Moreover, the effects of plate thickness and penetration depth have been considered. The aim of this work was to study the effects of these geometrical variables on fatigue SIF of the load-carrying welded joints with lack of penetration. The ability of FRANC2D to find an appropriate SIF solution is shown and compared with available solutions.     

Alkylpolyglucoside - Technologie und Eigenschaften

Alkylpolyglucosides - Technology and Properties. Carbohydrate derivatives with surfactant properties are known for a long time. Nevertheless, their large scale commercial production has not been realized in the past, especially due to the lack of suitable economical manufacturing procedures. Among the well-known carbohydrate surfactant structures, the long chain alkyl polyglucosides are expected to succeed within the group of large scale leading surfactants. The development of the chemistry of carbohydrate surfactants is reviewed, particulary describing manufacturing process options for alkyl polyglucosides. Present large scale glucoside surfactant manufacture is based on a number of decisive product and process improvements, leading to products which meet the demands of the surfactant market regarding performance, quality and price. Alkyl polyglucosides are a new category of mild, moderately foaming, highly soluble nonionic surfactants suitable for many applications and industries. Their unique performance and formulating properties are summarized.     

The impact of autonomous vehicle technologies on product recall risk

Complex Advanced Driving Assistance Systems (ADAS) and Autonomous Vehicle (AV) technology are increasing the number of vehicle recalls. At the same time, financial risks resulting from extensive product recall events can severely affect vehicle manufacturers and their suppliers, exposing the automotive supply chain to business continuity, legal and reputational risk. However, these risk implications are under-appreciated by large segments of the supply chain. This study shows that product recall events are increasing in general but recall events associated with ADAS/AV technology form an increasingly large percentage of these recall events. Based on this analysis, we describe ADAS/AV-specific aspects of risk mitigation and present a multidimensional approach, combining production-centric risk mitigation avenues in the automotive supply chain with the transfer of residual financial risks via insurance. We find that this comprehensive risk mitigation approach benefits in higher transparency of total production costs and increased resilience of the automotive supply chain. Against the background of an increasing product recall risk resulting from the increasing automation and interconnectedness of modern vehicles, we therefore suggest a closer, more strategic cooperation between insurance companies, car manufacturers and automotive suppliers for the benefit of all parties.     

The effect of tool vibrations on the flank surface created by peripheral milling

Tool vibrations have a significant influence on the surface quality with respect to surface location error and roughness. Even chatter-free milling processes can produce a high surface location error since chatter-free does not necessarily mean vibration-free. This article describes a geometric model for predicting the surface formation resulting from peripheral milling processes when tool vibrations are present. This model enables one to predict and minimize the roughness and location error of the flank surface. Comparisons between simulations and experiments show the effectiveness of this modeling approach. An important result of this research is that it has shown that milling at a stability maximum does not generally yield the best surface quality.     

Eine Methode zur Bestimmung von Wasserstoff,Sauerstoff und Stickstoff in niedrig sublimierenden Substanzen

A method for determining Hydrogen, Oxygen and Nitrogen gas concentration from materials, which sublimate at low temperatures . By application of the method Gas-Extraction with a special crucible-filter-system it is possible, to determine gas contents in the region of ppm from materials, which sublimate at low temperatures. The advantages of the High-Vacuum-Degasification in connection with Mass Spectrometric gas analysis, i. e. the detection of all gas components by using only one measurement, were used in this method.     

Möglichkeiten des Pflanzenschutzes mittels einer elektrischen Kondensatorvorrichtung

Zusammenfassung Es wird eine Kondensatorvorrichtung für Pflanzeschutzzwecke vorgeschlagen, in der eine—unter bestimmten Bedingungen zugleich vor Hagel schützende—netzartige Abdeckung als obere Elektrode des Kondensators ausgebildet und über dem als Gegenelektrode benutzten Erdboden elektrisch isoliert aufgestellt ist. Je nach der angelegten Spannung sind verschiedene Anwendungen dieser Vorrichtung denkbar, wie zum Ablagern von Schutzstoffen auf den Pflanzen, vielleicht auch als Elektroklimatorium oder zum Abtauen von Schnee- und Reifniederschl?gen, vor allem aber zum Frostschutz durch dielektrische Erw?rmung. Die Probleme der dielektrischen Erw?rmung werden besonders eingehend er?rtert. Dieser Aufsatz stellt im wesentlichen einen Versuch zu einer Synthese einschl?giger Folgerungen aus bekannten Tatsachen dar.