TY - CONF A1 - Schröpfer, Dirk T1 - Studies on the pore formation in super duplex stainless steel welds N2 - When welding super duplex stainless steels a non-admissible pore formation can occur even if recommended processing guidelines are followed strictly. To investigate this phenomenon and to determine the influencing factors different claddings were produced using gas metal arc welding and submerged arc welding. The welding consumables, the shielding gas and the welding flux were varied. As shielding gases several mixtures, based on argon and 30 % helium, with various amounts of nitrogen, nitric oxide, carbondioxid and oxygen were applied. As welding flux agglomerated fluoride basic fluxes and aluminate fluoride basic fluxes were used. Different batches of the similar solid filler wire G 25 9 4 N L were used to produce the claddings on the base material UNS32750. To determine the pore formation X-ray examinations and microsections were used, to analyze the chemical composition of the claddings melt extractions and spectrometric examinations were applied. Additionally, the microhardness and the ferrite number were detected. The studies have shown the shielding gas, the welding flux and the filler metal possess a great influence on the pore formation. Even small variations in the chemical composition of the welding consumables lead to totally different results. In addition, the ferrite number and the chemical composition of the claddings depend strongly on the used gases and filler metals. T2 - IIW Intermediate Meeting, C-IIA CY - Madrid, Spain DA - 29.02.2016 KW - Cladding KW - Welding KW - Duplex stainless steels KW - Pore formation PY - 2016 AN - OPUS4-38786 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Giese, Marcel A1 - Gräbner, Maraike A1 - Schröpfer, Dirk A1 - Treutler, Kai A1 - Lorenz, Svenja A1 - Kannengießer, Thomas A1 - Wesling, Volker T1 - Alloy modification and ultrasonic-assisted milling of wear-resistant alloys with defined surfaces N2 - The reduction of CO2 emissions is closely linked to the development of highly efficient and economical steel components in plant and process engineering. To withstand the high combined corrosive, tribological, thermal, and mechanical stresses, wear-resistant coatings tailored to the application and steel grade are used. In addition to the increasing demand to substitute conventional cobalt alloys with nickel alloys, there is also a growing need for defined or functional surfaces of high integrity. Due to high tool wear, milling operations required to produce the complex geometries of the components are often not economically feasible for SMEs. By means of alloy modification of the filler metals for nickel-based plasma build-up welded wear-resistant coatings and by the use of innovative ultrasonic-assisted milling processes more favourable machinability shall be achieved without reducing the wear protection potential. In this paper, the influence of the microstructure and precipitation morphology adjusted by means of alloy modification on the machinability is investigated. This is done based on a wear protection alloy NiCrMoSiFeB (trade name: Colmonoy 56 PTA) typically used for screw machines, which substitutes conventional CoCr alloys (Stellite). Metallurgical investigations and in-situ measurements of occurring process forces and temperatures at the tool cutting edge during milling as well as subsequent investigations of tool wear and surface integrity allow a detailed analysis and correlation between microstructural properties and machinability. For the cast samples, a clear change in the microstructure and hardness can be seen through the addition of Al, Ti, or Nb. These differences lead to an improvement in the machining process for Nb. Al and Ti cause long-needled or star-shaped precipitations and hardness increases, which lead to higher cutting forces and increased tool wear. KW - Cladding KW - Wear resistant alloys KW - Alloy modification KW - Post-processing KW - Ultrasonic assisted milling KW - Renewable energy PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-622918 DO - https://doi.org/10.1007/s40194-024-01786-6 SN - 1878-6669 VL - 68 SP - 2567 EP - 2575 PB - Springer Science and Business Media LLC CY - Berlin ; Heidelberg AN - OPUS4-62291 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Bäßler, Ralph T1 - Book review: Additive manufacturing of metals – From fundamental technology to rocket nozzles, medical implants, and custom jewelry N2 - This book fulfills its intention to provide a comprehensive overview on 3D-printing of metals. The interested reader can get a lot of information about the topics one should deal with when working with additively manufactured metallic parts. It gives a general roadmap where to start, what to learn and how it fits together. KW - Additive manufacturing KW - Alloys KW - Cladding KW - 3D-Metal-Printing PY - 2018 DO - https://doi.org/10.1002/maco.201870124 SN - 0947-5117 VL - 69 IS - 12 SP - 1881 PB - WILEY-VCH Verlag GmbH & Co. KGaA CY - Weinheim AN - OPUS4-46902 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -