Electroslag refining with liquid metal for composite rotor manufacturing
Journal Title: Archives of Materials Science and Engineering - Year 2018, Vol 2, Issue 91
Abstract
Purpose: To develop novel ESR based process for composite ingot with shallow transition zone between layers in order to produce efficient heavy-weight rotors for steam turbines. Design/methodology/approach: The nowadays heavy-weight rotors for steam turbines for power plants are monoblock or two or more layer in length composite part facilitating operation in different zones withstanding various loads and working medium. However, the joining of various steel in composite rotors by welding has low productivity. The ESR now is recognised as the best available technology for the big-diameter and mass forgings for power generating machines, including rotor ones. The ESR affords the most favourable conditions of solidification resulting in homogenous low-segregation ingot with smooth surface and high-quality structure. The step ahead is the ESR for composite. Findings: The two-layer model ingot had produced from steel grades 12Cr13 and 35NiCrMoV12-5 were manufactured using the electroslag process with the liquid metal (ESR LM) in the CSM of 180 mm in diameter with ingot withdrawing. The transition zone in two-layer ingot had have the shallow shape and low depth with the even macrostructure without defects of the same type as both joined steels. The metal of the transition zone fully satisfies standard requirements for properties of both steel grades in the heat treated and as-cast conditions. Research limitations/implications: The ESR LM can provide both the monobloc heavy ingots with uniform structure and composites with low-stress connection between metal layers for heavyweight rotors and other critical products manufacturing.<br/><br/>
Authors and Affiliations
L. Medovar, G. Polishko, V. Kostin, A. Tunik
Keywords
Related Articles
- EP ID EP389518
- DOI 10.5604/01.3001.0012.5489
- Views 54
- Downloads 0
Temperature changes influenced by different types of light curing units during polymerization of resin-based dental composite materials
Purpose: of this study was to evaluate the influence of LCU type on temperature changesduring polymerization of two resin-based composites with different matrices (silorane-basedand methacrylate-based).Design/methodology...
Effects of friction stir welding parameters on the mechanical properties of AA7075-T6
Purpose: In this paper, the mechanical properties of welded joints of AA7075-T6 obtained using friction stir welding (FSW) with five regimes of ratio of tool rotation speed to weld speed (3.0, 4.0, 7.5, 10...
Effect of post-weld heat treatment on thermal diffusivity in UNS S32304 duplex stainless steel welds
Purpose: The thermal diffusivity variation of UNS S32304 duplex stainless steel welds was studied after pulsed GTA welding autogenous process without filler addition. This property was measured in the transverse sectio...
The methods of globoid surface modeling in CAD
Purpose: Modeling of globoid worm surface is a difficult issue of modeling of complexsurfaces in CAD. Worm gears are a challenge for designers because of the constructionand the functions that have to be met, as well. Th...
Hardening strain and recovery strain in nanocrystalline Ni investigated in tests with multiple stress changes
Purpose: Dynamic recovery is interesting as it limits the maximal deformation strength of crystalline materials. Due to its small grain size, nanocrystalline Ni reaches its maximal strength after small stra...