The consequences of what has been termed running ductile fracture require that pipelines be designed to arrest propagation, and so avoid major incidents due to this type of failure. Approaches to characterize pipeline response and their resistance to such failure to ensure arrest rely on semi-empirical models developed in the mid-1970s. Continuing reliance on such semiempirical models, which were calibrated using fullscale tests done on segments of pipelines, persists because this failure process involves three interacting nonlinearities, and so is complex. These nonlinearities include: 1) plastic fl ow and tearing instability, 2) soil-structure interaction, and 3) expansion wave response and decompression in the pressurizing media. This paper first reviews the history and related developments that represent almost 40 years invested in fractureased approaches to quantify propagating shear in pipelines. Graphical evidence of the fullscale failure process and related phenomenology lead to an alternative hypothesis to quantify this failure process that is based on plastic collapse rather than fracture. It is shown that the phenomenology does not support a fracture-controlled process, and that instead the metrics of arrest should refl ect the flow properties of the steel. Finally, aspects of fracture-based approaches are related to the collapseased concept as the basis to understand the success that at times has been achieved using fracture-based approaches. Surrogates for CVN energy that has been used in the BTCM as a measure of fracture resistance are reevaluated as functions of the fl ow response, which provides the basis to rationalize the historic successes on the fracture-based formulation. Finally, remaining gaps and issues are addressed.

The optimal porosity of carbide frame is 44 ... 52 %. The author explored the kinetics of the process of impregnating of the green carbide frame of titanium carbide by steel 18Cr10NiTi and experimentally found dependence of the rate of impregnation of the distance of  1  cm from the contact surface of the steel with carbide frame. The dependence of the impregnation time from the pressing height was found. The regularities of distribution of grains of titanium carbide in pressing height after impregnation was determined and its dependence on recrystallization of carbide grains through the liquid phase was described. 

Results of calculation of the axial stress, the absolute margin of safety, safety I.L. Perlin factor for wire were determined and the authors proposed criteria for evaluating the effectiveness of forming
at drawing round solid profi le. At the optimum value of the angle of drawing, when the axial stress is minimal, can be observed maximum values of the safety factor and the proposed performance criteria of forming.

The article describes the results of theoretical and experimental studies of a new method of stamping with regulated heating of workpiece to a predetermined temperature and its subsequent deformation by bilateral exposure of combustion products of gas mixtures. The authors demonstrated the possibility of heating the formed preform directly into the die cavity until the hot working temperature range. At this time, heating of the billet is less than 1 s, and the pressure of the combustible gas mixture depending on the material and thickness of the preform is 0.5 ... 2.0 MPa. The dependences of the parameters are determined for the calculation of the stamping process. Experimental studies have shown that this method by heating the workpiece creates favorable conditions for its deformation. This provides stamping parts with complex shapes in a single technological transition, using relatively simple die tooling, signifi cantly reduces the cost of the stamped parts. Due to this and the low cost of the used equipment, this method of stamping can fi nd effective application in industrial production.

At present, one of the highly demanded types of metal products is steel pipe for constructional purposes. The most important characteristics are its   dimensional accuracy and surface fi nish, high level of mechanical properties and operating characteristics. Particular attention is paid to the precision of the internal channel of pipes, because this parameter determines the reliability and cost-effectiveness of their use. One of the most effective ways to increase the precision of the internal channel is pipe expansion by a mandrel. To investigate the accuracy of pipes a program of fi nite element simulation should be used. This has allowed us to investigate the extrafocal expansion at the inlet and outlet of the deformation zone, the inhomogeneity of deformation and the increasing pipe accuracy. The evaluation of these characteristics is an important factor for developing optimal conditions of deformation and tool design high-precision pipes in order to produce in terms of their inner diameter.

Urgent task for JSC “Ural Steel” is to determine the length of a rational supporting system on the frame of the mold to prevent the formation of bulges narrow edges of slabs with cross-sectional dimensions of 270Ч1200 mm. The technique is based on a comparison of the strength of the hardened crust narrow workpiece edge at different points in the length of the cast slab and the calculated value Expander pressure of liquid metal on the crust is used to solve this problem. Peel strength of the hardened slab in the possibility of plastic deformation of the shell may have yield strength of conventional cast steel. Experimental determination of the yield strength of cast steel grades 09G2S and 15HSND was conducted on high-temperature setting «Zwick  /  Roell Z1600H» in the temperature range 900–1400 °C. The value Expander pressure of liquid metal acting on the hardened crust slab was designed by the developed technique, which allows to take into account the specifi c conditions for the considered caster. Comparing the experimental and calculated values of the parameters established that the hardened crust of the narrow side of the slab thickness of 270 mm starts to withstand bursting pressure melt away from the metal mirror is equal to 1610  mm. With regard to the height of the metal mold (800 mm) length of the narrow sides of the support preform should be 810  mm. This can be possible if the number of support rollers with a diameter of 130 mm for each side of the workpiece is increased from four to fi ve. The studies identifi ed a rational extension of the supporting system located on the frame of the mold to prevent the formation of bulges narrow faces of slab blanks with cross-sectional dimensions of 270Ч1200 mm in terms of “Ural Steel”.

The article presents the results of investigation of the explosion welding of strips of spring steel with some sheet metals. The selection of metals and their properties are grounded. The results of the shooting of the compositions are presented. Recommendations for use of the compositions as armor elements and of selection of parameters of process for their production are given.

Arising in the process of upsetting of cylindrical workpieces stress-strain state has a signifi cant effect on the necessary consumer qualities of the fi nished products. Signifi cant infl uence on the fi nal distribution of strain and stress has the original aspect ratio of height and diameter of the workpiece. It is often diffi cult to analyze state of the metal in real conditions of upsetting, and sometimes it is impossible, but modern metgods of computer simulation allow to penetrate deep into researching process. To verify the adequacy of the data obtained in the Simufact Forming the authors made modeling of upsetting of three samples with different ratios of height and diameter (H0 / D0 : 3,75; 1,875; 1,25). Next, the simulation results (stress-strain state, metal fl ow, distribution power parameters of the process) were compared with the actual processes described in the literature. The obtained results allow to make a conclusion about high qualitative convergence of the produced simulation with real processes.

Thermodynamic analysis of oxygen solutions in the Fe – Ni – O, Fe – Co – O, Co – Ni – O melts was determined. Composition of the oxide phase and the value of the equilibrium oxygen concentration in the melt of those systems were fi rst time obtained in a whole range of alloy compositions. In Fe – Ni – O and Fe – Co – O systems with increasing content of nickel and cobalt in the melts the oxide phase contains mainly FeO in a suffi ciently wide range of content of nickel and cobalt. Only when the mole fraction of nickel is close to unity and the mole fraction of cobalt is more than 0.8, content of NiO and CoO increases sharply. Oxide phase of Co – Ni – O system contains CoO and NiO in
the entire range of alloy compositions. In the Fe – Ni and Fe – Co systems nickel and cobalt additives in the melt lead to decreased solubility of oxygen due to the attenuation, both nickel and cobalt, oxygen bonds in the melt and thus increases its activity. Further, by increasing the content of nickel and cobalt, the oxygen concentration in the melt increases slowly at fi rst and then quite rapidly. In Co – Ni system nickel additives to cobalt lead to increasing solubility of oxygen in the whole range of alloy compositions due to a substantially greater solubility of oxygen in nickel than in cobalt.

The regularities of dislocation accumulation at forming dislocation structure of deformed martensitic steel are established on the base of electron microscopy. The factors determining an intensity of dislo-
cation accumulation are revealed. Scalar dislocation density is divided into two components: density of geometrically necessary dislocations and density of statistically stored dislocations. The specifi c attention is given to geometrically necessary dislocations. Their accumulation in different substructure formations of the deformed steel is revealed. Critical grain sizes, when regularities of dislocation accumulation are changed, are determined