A model to predict fatigue crack growth of API pipeline steels in high pressure gaseous hydrogen has been developed and is presented elsewhere. The model currently has several parameters that must be calibrated for each pipeline steel of interest. This work provides a sensitivity analysis of the model parameters in order to provide (a) insight to the underlying mathematical and mechanistic aspe...

Different techniques have been investigated to seek the best procedure to reveal the prior-austenite grain boundaries in three medium-carbon microalloyed steels. This study has been carried out over a wide range of temperatures (950–1250 C) and it has been found that thermal etching (TE) is the best technique to reveal the prior-austenite grain boundaries in these steels. D 2001 Elsevier Scienc...

The freezing process. microstructures and phase relationships in some experimental cast tool steels have been investigated and developed under the various solidification conditions. Experimental steels were based on AISI M2 and M10 grades high speed steels. Addition of carbide forming elements such as niobium and titanium with and without extra carbon were made to the molten bath of the base st...

An arrangement of double pseudolines is a finite family of at least two homotopically trivial simple closed curves embedded in the real projective plane, with the property that any two meet exactly four times, at which points they meet transversely, and induce a cell structure on the real projective plane. In this talk I will show that any arrangement of double pseudolines is isomorphic to the ...

The structural view of rational acceptance is a commitment to developing a logical calculus to express rationally accepted propositions sufficient to represent valid argument forms constructed from rationally accepted formulas. This essay argues for this project by observing that a satisfactory solution to the lottery paradox and the paradox of the preface calls for a theory that both (i.) offe...

Recent research suggests that extraordinary combinations of strength and ductility can be achieved in the so–called δ–TRIP steels, which contain ferrite, bainite and austenite. A part of the reason for the ductility of almost 40% elongation at a strength of some 900MPa, is believed to be the optimal stability of the austenite to plastic deformation. We demonstrate here that mechanical stabilisa...

We prove the triviality of the Grothendieck ring of a Z-valued field K under slight conditions on the logical language and on K. We construct a definable bijection from the plane K to itself minus a point. When we specialize to local fields with finite residue field, we construct a definable bijection from the valuation ring to itself minus a point. At the Edinburgh meeting on the model theory ...

In the contribution the stress of die materials of thermal fatigue is defi ned and material life is derived theoretically and compared with the measured values. The important properties of the die materials as thermal conductivity, coeffi cient of thermal expansivity, modulus of elasticity and mechanical properties are described. Binding to it single die materials as carbon steels and chrome-tu...

There has been a huge expansion in the laying of pipelines for the transmission of fossil fuels over large distances and in dire environments. One particular problem associated with the steels used to fabricate the pipes is that of the anisotropy of mechanical properties, especially the toughness. This review represents an attempt to critically assess the steels and the orientation dependence o...