Technological properties of Al—Mg—Si alloys during manufacturing of thin-walled tubular products using welding and reduction

2021 ◽  
pp. 348-353
Author(s):  
V.S. Muratov ◽  
M.S. Kazakov
Keyword(s):  
Heat Affected Zone ◽  
Technological Properties ◽  
Welding Zone ◽  
Aged State ◽  
Thin Walled

The reasons for the appearance of cracks during the reduction of filling nozzles made by using welding from the Al—Mg—Si alloy bars are studied. It is found that the cause of fracture is the embrittlement of the alloy and the deterioration of its deformability in the heat-affected zone of welding. Recommendations for eliminate the deterioration of the deformability of the alloy during the intensification of the cooling of the welding zone are developed, which makes it possible to preserve the zone-aged state in the heat-affected zone.

Microstructure and Properties Analysis of Inner Cladding Tube and End Plug Girth Weld of Annular Fuel Element

2017 ◽  
Author(s):  
Ji Pengbo ◽  
Lu Hanghang ◽  
Wang Zhaosong ◽  
Zhang Zhoufeng ◽  
Liu Bin
Keyword(s):  
Fuel Element ◽  
Heat Affected Zone ◽  
Welded Joints ◽  
Weld Zone ◽  
Tensile Fracture ◽  
Massachusetts Institute Of Technology ◽  
Micro Hardness ◽  
Welding Zone ◽  
Pressurized Water ◽  
Institute Of Technology

Annular fuel element is a kind of new double-sided fuel element, and the welding between the inner cladding tube and end plug of it belongs to a new kind of welding. Actually the conception was first proposed by Massachusetts Institute of Technology and the China Institute of Atomic Energy of Reactor Engineering makes the physical design of annular fuel element product. Through this research, we now basically master the method of welding annular fuel element. In this research, we designed a girth-welding fixture for welding the inner cladding tube and end plug of annular fuel element. The influences of the power input on the weld penetration and morphology have been obtained. The metallurgical performance of welded joints was analyzed through optical microscope, hardness testing and scanning electron microscope (SEM). The mechanical tests results indicate that the tensile properties of the welded joints are closely related to the microstructure. And the welding joints are also tested in the autoclave. The research shows that the micro hardness along the longitudinal section of the inner cladding tube appears to be the trend: firstly gradually reduced, and then stayed. The highest hardness is in the welding zone. And the heat-affected zone has great impacts on the micro hardness: the far the area is away from the welding line, the lower the micro hardness becomes. The grains in both of the weld zone and heat-affected zone are obviously grown up, but the grain growth is more obvious in the weld zone. The tensile fracture of the welding joint all occurs in the welding zone, the tensile strength is larger than that of the bar, which is used for processing the end plug. And the maximum force belongs to the shear stress fracture. In microstructure picture, the weld fracture appears to be dimple-shaped. And some of the dimples showed equiaxial and some of the dimples showed the elongated dimples. And the surface-welding zone is coated with the uniform and compact black oxide film without the white and brown corrosion. All the results and study in the paper will be of guidance for the further processing of the annular fuel element used in the pressurized water reactor (PWR).

scholarly journals Selected Technological Properties of Liquid Ceramic Slurries Used to Produce Moulds in the Replicast cs Technology

2017 ◽  
Vol 17 (4) ◽  
pp. 190-194
Author(s):  
R. Kaczorowski ◽  
P. Just ◽  
T. Pacyniak
Keyword(s):  
Production Process ◽  
Apparent Viscosity ◽  
Computer Image ◽  
Wetting Angle ◽  
Special Role ◽  
Technological Properties ◽  
Ceramic Slurry ◽  
Thin Walled

Abstract The study discusses the issues connected with the production of thin-walled ceramic slurry in the replicast cs technology. In the ceramic mould production process, a special role is played by the liquid ceramic slurry used to produce the first layer of the mould. The study examines selected technological properties of liquid ceramic slurries used to produce moulds in the replicas cs technology. The ceramic slurries for the tests were prepared based on the binders Ludox Px30 and Sizol 030, enriched with Refracourse flour. The wettability of the pattern's surface by the liquid ceramic slurry and the dependence of the apparent viscosity on the ceramic flour content in the mixture were determined. The wettability of the pattern surface by the liquid ceramic slurry was determined based on the measurement of the wetting angle. The angle was determined by means of an analysis of the computer image obtained with the use of a CDC camera.

Dynamic recrystallization of friction welded AISI 316 stainless steel joints

2020 ◽  
Vol 62 (11) ◽  
pp. 1126-1130
Author(s):  
Sare Celik ◽  
Ismail Ersozlu
Keyword(s):  
Stainless Steel ◽  
Dynamic Recrystallization ◽  
Heat Affected Zone ◽  
Friction Welding ◽  
Welding Zone ◽  
Hollomon Parameter ◽  
316 Stainless Steel ◽  
Aisi 316 Stainless Steel ◽  
Aisi 316 ◽  
Individual Grains

Abstract The microstructural characteristics of friction welded AISI 316 stainless steel samples in a welding zone and a heat affected zone were investigated. Inhomogeneous plastic deformation occurred due to friction welding. Individual grains in the final microstructure underwent various evolution mechanisms. These were caused by the growth of the initially recrystallized grains or as a result of the dynamic recrystallization of the sub-grains formed. The grains within the welding zone and the heat affected zone exhibited different densities of dislocations and experienced various degrees of recovery. Using reasonable estimates of the strain, strain rate and temperature of the friction welding, the dependence of the dynamic recrystallization grain size was found to have the same dependence on the Zener-Hollomon parameter as material deformed via a conventional hot working process.

Operation intensification methods of aggressive industrial sewage neutralization facilities

2020 ◽  
Vol 76 (11) ◽  
pp. 1149-1153
Author(s):  
N. S. Tsarev ◽  
V. I. Aksenov ◽  
I. I. Nichkova
Keyword(s):  
Cold Water ◽  
Specific Productivity ◽  
Technological Properties ◽  
Technological Parameters ◽  
Preliminary Heating ◽  
Sediment Treatment ◽  
Circulating Water ◽  
Equipment Operation ◽  
Sediment Volume ◽  
Industrial Sewage

To neutralize the waste pickling solutions and rinsing water, resulting from cleaning metal products s surface of rust by acids solutions, lime is used. Being cheap, this method of sewage neutralization has considerable drawbacks. Forming in the technological pipes strong gypsum depositions and low specific productivity of the equipment for sediment dewatering are most significant of them. Characteristic of aggressive industrial sewage, formed at pickling of ferrous metals presented. Methods of elimination of drawbacks of industrial sewage neutralization by lime considered, including stabilization of neutralized industrial sewage and control of properties of the sediment formed. It was noted, that stability of the circulating water can be provided by accelerating of crystallization of the forming gypsum sediments by introducing in it fine priming powder and heating the neutralized water up to 65-70 °С followed by thermal softening of a part of circulating water, removed out of the circulating system. It was shown, that the heating of the water and the ongoing changes of the composition and properties of the sediment result in decrease of filtration resistance 2-3 folds, increase of deposition speed 3-4 folds and decrease the sediment volume 1.5-2 folds comparing with lime neutralization in cold water. Calculated dozes of lime at the heating were taken the same as at the regular lime neutralization. Elimination of the circulating water oversaturation by bi-water gypsum can be reached also by addition into the water of powder-like gypsum pulp - priming powder for microcrystals of the gypsum, followed by aeration during 30-40 min. This method was tested under industrial conditions. Technological properties of the forming sediment can be improved by sediment treatment by flocculants and preliminary heating of the neutralized water up to 65-70 °С. Control of technological properties of the sediment is done by addition of flocculants and heating of the neutralized water. Recommendations for improving operation of the neutralization facilities presented with indicating particular technological parameters of the equipment operation for sewage and sediment treatment. 

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