Specialists of PJSC Energomashspetsstal (EMSS, Donetsk region, Ukraine) have mastered a new technology for manufacturing shanks and discs of low-pressure rotors, which made it possible to successfully pass the qualifications of General Electric and start serial production of products.
“Work on preparing EMSS production for qualification has been carried out for a long time and was completed in the fall of 2019. The qualification procedure itself lasted a whole year. In order to achieve this goal, General Electric developed a qualification plan, according to which drawings and requirements for test products were sent to EMSS. In a short time, the technological divisions of EMSS developed plans for the production process for the manufacture of shanks and rotor discs, which were sent to General Electric and approved by them, "says Alexander Lobanov, head of the forging department, deputy technical director for production preparation at EMSS PJSC.
Among the main conditions for passing the qualification is the accreditation of the EMSS testing laboratory for compliance with the requirements of the ISO /IEC 17025: 2017 standard. To ensure compliance with the customer's requirements, the central plant laboratory EMSS carried out serious work on their implementation. The proof of the technical competence of EMSS was the successful accreditation of the Central Laboratory of PJSC EMSS for compliance with ISO /IEC 17025: 2017, which took place in March 2020.
The result of the work done was the opening in October 2019 of a qualifying order for the manufacture of two experimental forgings "Shank" and "Disk". The uniqueness of these products was in ensuring strict requirements for the continuity of products with their large dimensions: the finished size of the finished "Disk" was about 3 meters in diameter, height - 1.3 meters, delivery weight - about 40 tons. For "Shank" the delivery weight was 54 tons.
In order to obtain the required characteristics, for the first time on EMSS a new scheme for forging billets with normalized reduction was tested and showed a successful result. The new technology makes it possible to achieve customer requirements in terms of the integrity of the structure of parts.
“In order to comply with General Electric's requirements for qualified metal, both“ Shank ”and“ Disk ”had test sites, according to the results of metal testing, the quality of the product was assessed. Sampling under qualification conditions was carried out both from the surface of the workpiece and from the axial zones of the "Shank" and "Disk". In all sampling points, tests were carried out, which confirmed the uniformity of the properties of the products over their cross section. It should be noted that the absence of defects and the uniformity of the structure of the products was confirmed by the experts of Bureau Veritas and General Electric, ”says Alexander Lobanov.
The result of this difficult and interesting work was the successful completion of the qualification, which allowed EMSS to start the serial production of parts of low-pressure turbine rotors for General Electric, which will be installed at the Akkuyu NPP under construction in Turkey. To date, orders for two rotors have already entered production.