Inspired by a problem in steel metallurgy, we prove the existence, regularity, uniqueness, and continuous data dependence of solutions to a coupled parabolic system in a smooth bounded 3D domain, with nonlinear and nonhomogeneous boundary conditions. The nonlinear coupling takes place in the di usion coefcient. The proofs are based on anisotropic estimates in tangential and normal directions, a...

We delimit a classification matrix of companies formed by four quadrants, defined by the Present Value of Growth Opportunities and by the Naïve Net Present Value. Market data relative to companies that have stock negotiated on the Brazilian stock exchange (the São Paulo Stock Exchange Bovespa) for the years 2005 and 2006 were utilized. The retail, textile, iron and steel, and metallurgy, petrol...

Powder metallurgy has been used for the manufacture of fully dense, which have not reacted composites consisting of a matrix of copper containing 50 -60 vol% particles with negative thermal ZrW2O8 expansion. On cycling between 25 and 300°C, the compounds showed coefficients thermal expansion which varies rapidly with temperature and significantly larger than expected by theory. Improvements in ...

B. Gajdzik, The Silesian University of Technology, Faculty of Materials Science and Metallurgy, Katowice, Poland J. Sitko, The Silesian University of Technology, Faculty of Organization and Management, Zabrze, Poland The publication presents the causes of complaints about metallurgical products, illustrated with an example of steel sheets, with a particular focus on the reasons having their sou...

A PM approach is investigated in the context of extremely fine low temperature bainitic steels with a reasonable combination of ultimate tensile strength and uniform elongation. The strategy consists of three steps. First, ball milling is used for mechanical alloying and to create a large density of interfaces prior to sintering. In the second step, spark plasma sintering is used as a rapid con...

Powder metallurgy (P/M) technique is usually used for manufacturing porous metal materials. However, some P/M materials are limitedly used in engineering for their performance deficiency. A novel 304 stainless steel P/M material was produced by a solid-state sintering of 304 stainless steel powders and 304 short stainless steel fibers, which were alternately laid in layers according to mass rat...

A theorem of this paper proves that if the size distribution of random spheres is generalized gamma, its Wicksell transform and other related distributions belong to the domain of attraction of the Gumbel distribution. The theorem also shows the attraction coefficients of the distributions. The fatigue strength of high-strength steel is closely related to the maximum size of nonmetallic inclusi...

Modern steel making processes are based on electrical arc furnaces (EAF) or converters, secondary metallurgy and CSC equipment. Steel casting processes are carried on as the continuous ones, which today are the dominating methods in global quantities of steel production. These methods make possible production of the continuous castings of predetermined profiles and dimensions, and therefore to ...