RU-2861701-C1 - METHOD FOR MANUFACTURING HOUSING PARTS OF SGTU USING ELECTRIC ARC SURFACING TECHNOLOGY

Abstract

FIELD: additive technologies. SUBSTANCE: invention relates to a method for manufacturing a pre-chamber housing of a small-sized gas turbine unit (SGTU). A workpiece of the SGTU pre-chamber housing is obtained from metal wire made of stainless steel “12Х18Н10Т” using electric arc surfacing technology followed by machining. Electric arc surfacing is carried out under the following conditions: spot diameter 2-2.5 mm, bead height 2-2.5 mm, bead width 5.6-6.4 mm, bead length 120 mm, welding current 180-220 A, welding voltage 12-24 V, tool speed 8-18 mm/s, bead overlap 60%, wire feed 4.3 m/min, shielding gas flow 14 l/min, technological pause between beads 30 s. Then, turning of ends, finishing turning of connecting surfaces of flanges, finishing boring of the inner surface and a milling-drilling operation for processing pre-chamber wells and drilling 24 blind holes at ∅149+0.052 mm to a depth of 11.5 mm and 72 blind holes at ∅191+0.052 mm to a depth of 13.5 mm, as well as cutting M5×0.75 threads, are carried out, ensuring a roughness of Ra 1.6 and a strength of 842 MPa. EFFECT: high level of mechanical characteristics of products and material roughness. 1 cl, 3 dwg, 1 tbl

Inventors

• Smelov Vitalij Gennadievich
• Balyakin Andrej Vladimirovich
• Borodkin Ilya Dmitrievich
• Gimranov Zafar Ilyasovich

Dates

Publication Date

20260507

Application Date

20241209

Claims (1)

1. A method for producing a pre-chamber body for a small-sized gas turbine unit (MGTU) including the technology of electric arc growth from metal wire, characterized in that a metal wire made of 12X18N10T steel is used as raw material for the blank, electric arc growth is carried out with the formation of surfacing beads under the following conditions: spot diameter 2-2.5 mm, bead height 2-2.5 mm, bead width 5.6-6.4 mm, bead length 120 mm, welding current 180-220 A, welding voltage 12-24 V, tool speed 8-18 mm/s, bead overlap 60%, wire feed 4.3 m/min, shielding gas supply 14 l/min, technological pause between beads 30 s, after which turning of the ends, finish turning of the connecting surfaces of the flanges, finish boring of the inner surface and milling and drilling operation for processing the wells of the pre-chambers and drilling 24 blind holes of ∅149+0.052 mm to a depth of 11.5 mm and 72 blind holes of ∅191+0.052 mm to a depth of 13.5 mm, as well as cutting M5×0.75 threads to ensure a roughness of Ra 1.6 and a material strength of 842 MPa.

Description

The invention relates to additive technologies, namely to the production of a pre-chamber body for a small-sized gas turbine unit (MGTU) using electric arc growth (EAG) technology with metal wire made of 12Kh18N10T material, followed by mechanical processing operations. Traditionally, pre-chamber housings are manufactured by casting and subsequent machining. This manufacturing process is time-consuming, expensive, and labor-intensive, requiring extreme precision and adherence to manufacturing requirements. The performance of a pre-chamber body is determined by its short-term strength, creep, and fatigue. These performance characteristics are directly dependent on the structural and phase state formed during casting. When using casting technology to manufacture pre-chamber bodies, casting defects are observed due to looseness and shrinkage porosity, which leads to a high rate of defects and uneven mechanical properties. A method for producing large-size, thin-walled, special-purpose castings using investment casting is known (RU Patent No. 180846, IPC B22C 9/04, April 15, 1993). The invention relates to foundry industry, specifically to the production of large-size, thin-walled, special-purpose castings using investment casting. The method involves lining the bottom and side walls of the flask with a heat-insulating refractory filler before placing the crystalline quartz-based mold shells in the flask. After the molds are installed in the flask, the gap between the mold sprue cups and the flask is sealed from above with a plate made of the same refractory filler, with openings for the sprue cups. A disadvantage of this method is the complexity and labor-intensive nature of the process, associated with the manufacture of the investment pattern and additional processing operations. This leads to high costs and increased time expenditures for manufacturing the pre-chamber body using this method. The development of optimal casting modes for MSTU components is of current importance and requires the resolution of a number of issues, both in technology and in metallurgy. To optimize the casting process, additive technologies are used at the investment casting stage. For example, 3D printing with natural PLA plastic using FDM technology. A "Method for Growing Large-Size Thin-Walled Models of Engine Component Castings Using 3D Printing Technology" is known (RU Patent No. 2807273, IPC B22C 7/00, B29C 39/02, B29C 33/40, B29C 67/20, published on November 13, 2023). The invention relates to foundry production using disposable models, namely the manufacture of large-size models for casting using burnt patterns using FDM additive technology, in particular to a method for growing large-size thin-walled models of engine component castings using 3D printing technology. The method involves producing large-scale, thin-walled casting patterns from natural, low-ash, pure PLA plastic using an FDM printer. The pattern is separated from the gating system (GS), the GS elements are grown as hollow parts at speeds of up to 150 mm/s, with an internal fill rate of 2 to 5% for the model and the remaining GS elements, and the casting parts are subsequently bonded and sealed. A disadvantage of this method is the need to produce a burnt-out pattern, which complicates the manufacturing process of the prechamber housings and thus increases its cost. The most cost-effective and highly productive method for producing complex-shaped prechamber body blanks is additive manufacturing using direct energy and material input. This method allows for the production of blanks directly from an electronic geometric model, eliminating the intermediate step of producing a lost-wax or burnt-out pattern, which are used in casting technology. The closest analogue is the method of manufacturing a high-precision blank from titanium alloy powder (RU Patent No. 2709694, IPC B23K 26/342, B23K 26/60, B22F 3/105, C23C 4/12, C23C 4/18, B33Y 10/00, published 2709694). A method for manufacturing a high-precision workpiece from titanium alloy powder, including layer-by-layer growth of the workpiece on a direct laser growth unit using data from a 3D model of the workpiece in the software or program data entered manually by the operator from the operator console, focusing laser radiation in a sealed working chamber in the powder processing zone using the optical system of the laser head, feeding powder into the laser radiation impact zone and layer-by-layer deposition of layers of the workpiece from the powder by moving oscillated laser radiation, characterized in that the layer-by-layer deposition of layers of the workpiece from the powder is carried out in a sealed working chamber filled with argon to excess pressure, wherein the laser radiation is oscillated using an oscillation module built into the laser head, with a frequency of 300-1000 Hz and an amplitude of 0.5-5 mm, wherein the power of the laser radiation is changed according to the program by points in the range