Spontane Ausbildung von Diffusionsbarrieren in Alitierschichten auf Nickellegierungen

Studium der Aluminiumeindiffusion in verschiedene Legierungen. Einfluß der Legierungszusammensetzung auf die Gefügeausbildung der Diffusionsschicht und die Wachstumskonstanten der gebildeten Phasen. Beschreibung der Sperrschichtausbildung in Nickellegierungen. Abhängigkeit der Sperrwirkung von dem Gehalt des Substrats an sperrschichtbildenden Elementen. Diskussion von Maßnahmen, um die Ausbildung von Sperrschichten in Nickellegierungen zu verstärken.     

Political correctness and "sexual harassment".

Examines political correctness (PC) and sexual harassment (SH). Because PC is such a multi-faceted phenomenon, certain limitations are imposed on the discussion. Here, only those aspects of PC will be examined that have immediate and important consequences for the debate about SH and the implementation of SH policies. These aspects are the following: (1) the intolerance of nonconformity, (2) the claim that PC is a sensitive and therapeutic doctrine, (3) and the moralism and paternalism of PC. What will be left out of the discussion are questions of group-think and group identity, questions of diversity, deconstructionism, new historicism, equity, and preferential hiring. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Möglichkeiten und Grenzen siliciumhaltiger Auflageschichten auf Nickellegierungen

Allgemeine Verfahren zur Aufbringung siliciumhaltiger Schutzschichten. Entwicklung eines neuen Beschichtungsverfahrens über einen Reaktionssinterprozeß unlegierter Auflageschichten. Einfluß der Schicht- und Substratzusammensetzung auf die chemische Kompatibilität des gesamten Schichtverbundes. Studium der Wirkung von Zwischenschichten auf die Reaktivität von siliciumreichen Auflageschichten auf Nickellegierungen. Vergleichende Kurzzeit- (Thermowaage) und Langzeitoxidationstests (Brennergas) bei 1000°C.     

Improvement of the Corrosion Resistance of High Alloyed Austenitic Cr-Ni-Mo Stainless Steels by Solution Nitriding

Characteristic features of austenitic steel grades combine a good corrosion resistance with a low hardness, wear resistance and scratch resistance. An interesting possibility for improving the wear behaviour of these steels without loss of their corrosion resistance lies in enriching the near surface region with nitrogen. The process of a solution nitriding allows the rise of the solution of nitrogen in the solid phase. On this state nitrogen increases the corrosion resistance and the tribilogical load-bearing capacity. The aim of the study was, to investigate the improvement of the pitting corrosion behaviour by solution nitriding. A special topic was to observe the effect of nitrogen by different molybdenum content. So austenitic stainless steels (18% Cr, 12% Ni, Mo gradation between 0.06 to 3.6%) had been solution nitrided. The samples could be prepared with various surface content of nitrogen from 0.04 to 0.45% with a step-by-step grinding. The susceptibility against pitting corrosion of these samples had been tested by determination of the stable pitting potential in 0.5M and 1M NaCl at 25℃. For the investigated steel composition and the used corrosion system there is no influence of molybdenum on the effectiveness of nitrogen. The influence of nitrogen to all of the determined parameters can be described well by PRE = Cr 3.3 * Mo 25 *N. XPS analysis of the sample surfaces support the results of the pitting corrosion tests.Additionally surface investigations with an acid elektolyte (0.1M HCl 0.4M NaCl) were performed. In this case the passivation effective nitrogen content increases markedly with rising molybdenum concentration of the steel.Obviously an interaction of Mo and N is connected with a strongly acid electrolyte.     

Effect of solidification conditions on the solidification sequence of austenitic chromium-nickel stainless steels

Unlike the well-known effect of alloy elements in promoting the ferritic or austenitic solidification of stainless and acid-resisting chromium-nickel steels, kinetic effects have as yet not been so widely looked into. For this reason, the impact of the solidification rate on the ratio of the amounts of ferritic and austenitic liquid solidification was investigated for the steels of grades X8CrNiTi18.10 and X8CrNiMoTi18.11. A microanalysis for the determination of the primary ferrite content of samples taken from ingots of different size and at different distances from the ingot surface for a total of 161 heats revealed the following:

• – Increasing solidification rate causes the primary ferrite content produced during solidification to rise for steels with peritectic solidification sequence due to the resultant approach of the distribution coefficient to unity.
• – Increasing solidification rate causes the austenite content to rise for steels with a primary simultaneous crystallization of austenite and ferrite due to a low total segregation in case of austenite crystallization as compared with ferrite crystallization.
• – The effect of an elevated solidification rate is qualitatively equivalent to a shift of the saturation lines of the three-phase space l+δ+γ in the Fe—Ni—Cr ternary system for liquid and γ-crystals in the direction S with the two saturation lines approaching each other. Hence, contrary to what is expected according to the equilibrium diagram of Schürmann and Brauckmann, austenitic Cr—Ni steels solidify primarily in peritectic mode and, in the area of the line of the double-saturated liquid, through a primary simultaneous crystallization of austenite and ferrite.
• – The boundary composition between primary ferritic and primary austenitic crystallization changes with an increase in cooling rate by seven orders of magnitude from 1.25 to 1.70 as expressed in the ratio of the Cr—Ni equivalents according to Hammar and Svensson.

     

Bandler and Grinder's neurolinguistic programming: Its historical context and contribution.

Reviews the historical context out of which R. Bandler and J. Grinder's (1975, 1976, 1979) theory of neurolinguistic programming emerged, in order to provide some insight into the theory's underlying premises. Influences from Husserl's phenomenological philosophy; W. Wundt's study of language, myth, and custom; and C. Rogers (1951) and Chomsky (1957) are discussed. Borrowing extensively from Chomsky's (1947) theory of transformational grammar, Bandler and Grinder outlined a step-by-step analysis of a client's language as presented in therapy, the surface and deep meanings of these structures, and specific meanings of these structures. Communication analysis has championed the existence of innate unobservable processes that influence communication, but it is limited by the lack of empirical research and the failure to recognize the importance of environmental influences on behavior. As an alternative to the narrow approach it is welcome, but in many ways the innate mechanisms of their neurolinguistic programming cannot account for all verbal behavior. It is concluded that experimental examinations will help to clarify the neurolinguistic programming model and its effectiveness and may lead to future improvements. (9 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Commentary.

Comments on the articles of J. J. Furedy (see record 199801996-002), O. E. Favreau (see record 199801996-003), C. Stark (see record 199801996-005), D. Kimura (see record 199801996-006), and K. S. Dobson (see record 199801996-007), on the multifaceted topics surrounding political correctness in academia, including academic freedom, and women's issues. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Component specific influences on the fracture behaviour of high speed steels under static loading

This paper presents the first results of a series of investigations into the fracture behaviour of high speed steels with regard to component specific influences. The aim of the investigations was the analysis of the interaction of internal and external notches during the fracture process. Hardened and tempered high speed steel S 6-5-2 of various degrees of hot forming, which was produced by electroslag remelting, as well as powder-metallurgically produced high speed steel ASP 23 were tested to investigate the influence of different carbide sizes and distribution. In-situ bend tests showed the role of the carbides as fracture initiating defects, which form subcritical cracks as a result of the higher stiffness and lower failure stress at loads smaller than the global failure load of the specimen. The observed fracture process was simulated by FEM using the observations and results of the in-situ bend tests. The interaction of internal flaws and external notches was proven using notched and coated specimens as well as specimens of various surface roughness. The fracture initiating defect is the largest defect in the loaded volume regardless of whether it is an internal flaw (carbide) or an external notch (surface roughness, surface layer). Information can be derived from the investigations allowing the optimisation of the manufacture of high speed steel tools with regard to their fracture behaviour.     

On the Oxidation of (β-Stannylvinyl)phosphines: Chemical and spectroscopic effects

Both E- and Z-(β-stannylvinyl)phosphines are readily converted to the corresponding phosphine oxides by KMnO₄ in acetone. However, the less reactive oxidising agents MnO₂ and O₂ react selectively with only the E isomers. N.m.r. studies indicate that this may be due to interactions between the phosphorus lone pair and the triorganostannyl moiety in the Z-isomer, which make the latter less susceptible to attack. N.m.r. parameters for the phosphines and their oxides are compared.