Effect of heat treatment on mechanical properties and structure of high-strength pipe steels with a ferrite-bainite structure*

The effect of heat treatment on mechanical properties and microstructure of high-strength low-alloy ferrite-bainite pipe steels is studied. Specimens are heated in a laboratory furnace up to a temperature in the range 100?C850°C. Dependences for the change in mechanical properties on heating temperature and the main features of steel structure are determined. TEM is used to study excess phase precipitation, including Nb and V carbonitrides, during heating. Unfavorable temperature ranges are determined for heating pipe steels with a ferrite-bainite structure. The results obtained may be used in industrial production and during development of new technology for thermomechanical treatment.     

On right-hand uniqueness of solutions to nondegenerated algebro-differential equations with discontinuances

A finite-dimensional nondegenerate system of algebro-differential equations with discontinuances is considered. An equivalent system of discontinuous differential equations is constructed. Conditions of right-hand uniqueness of solution and of convergence of numerical methods are given.     

Structure and strain hardening of a Ti-40 at % Nb alloy produced by equal-channel multiangular pressing and hydroextrusion

The effect of a combined treatment, which includes nonmonotic deformation by equal-channel multiangular pressing and monotonic forming by hydroextrusion, and subsequent heat treatment on the structure, phase composition, and strength of an Nb-60 at % Ti alloy has been studied.     

Manufacture of rolled products for 762-mm-diam. Cold-resistant conductor pipe having a wall thickness of 38.1 mm and an X56 strength rating; Analysis of the tube conversion for this product

Specialists at the company Severstal’ and the Central Research Institute of Ferrous Metallurgy have developed a chemical composition and technology for making steel of strength class X56, and they have also produced a commercial batch of this steel. Production of the batch on the 5000 mill at Severstal’ entailed the use of a modern controlled-rolling technology together with accelerated cooling, which made it possible to obtain the required set of characteristics in thick plates. The Vyksa Metallurgical Plant converted the plates into 762-mm-diam. conductor pipe with a wall thickness of 38.1 mm. Analysis of the effect of the tube conversion on the mechanical characteristics of the steel showed that the changes which take place in the mechanical characteristics of the base metal during the formation of thick-walled tubes must be taken into account when specifications are developed for the flat-rolled products used to make these tubes.     

Change in Properties of Pipe Steel with Two-Phase Structure During Low-Temperature Heating and Subsequent Plastic Deformation

Metallurgist - Results are given for evaluation of the effect of longitudinal deformation on the change of the mechanical properties and steel properties with a two-phase pipe metal structure...     

Method of initial functions: stable algorithms in the analysis of thick laminated composite structures

Exact three-dimensional elasticity solutions for some static and dynamic problems of bending multi-layered anisotropic rectangular plates are presented. They are derived by the method of initial functions without employing any hypotheses about the character of the stress-strain state of the linearly elastic anisotropic structures. Two computationally stable algorithms of the method which extend the field of its application are developed. The results presented illustrate some possibilities of the designed stable algorithms. The analysis of multi-layered plates under concentrated static and harmonic dynamic loads are presented.