Entwicklung eines technologischen Verfahrens zur Herstellung von Panzerschichten mit Hartstoffpartikeln

Translated title of the contribution: Contribution to the weld process development of wear-resistant layers including hard-faced particles

Stefan Barwart

Research output: ThesisDiploma Thesis

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Abstract

Shredding-tools of crushing-units are mainly used for the recycling of solid waste. They are exposed to enormous local mechanic and abrasive loads. One method to improve the durability is to apply hard facing to the teeth cutting surfaces. Hard faced layers consist of iron based welding combined with tungsten carbides. These carbide particles should be spread homogenously into the molten ductile iron matrix leading to a ductile and most abrasive resistant filler metal. The generated composite, which is added on the substrate by an overlay-welding, relates to the requirements in practice, which should combine an optimum of low costs and sufficient fatigue-wear-life. Hard faced shredding-tools, which are highly resistant to abrasion and impact loads, can be easily manufactured with this particle-based dispersive method. The verified insertion of the hard particles into the filler-metal is therefore essential for the welding-process. It is well known from literature that these complex surfaces exhibit extreme brittle structures and get easily affected by cracks already at manufacturing stage. These cracks can lead increased rupture failure of the cutting-tools. The work focuses on the examination of extensive studies to determine the influence of the filler-material and the hard-tungsten particles to achieve an optimized most-homogenous welding-process. Thus different filler-composites, depending on the filler-material itself, the amount and distribution of the tungsten carbides and the different welding process parameters, were investigated as string bead technique on plain steel plates. A specific conveyer technique was build-up to achieve a continuous flow of the hard-phase particles as auxiliary weld unit. To rank the weld matrix, extensive metallographic analysis, macro-hardness measurements and topographical assessments were done. The optimized weld process lead to a most homogeneous distribution of the hard faced tungsten particles and a minimized occurrence of surface cracks. It has to be stated that the given results are only valid for this specific material and weld process combination. Finally, the optimized weld process was transferred from test plates to industrial chopping teeth´s with complex geometry.
Translated title of the contributionContribution to the weld process development of wear-resistant layers including hard-faced particles
Original languageGerman
QualificationDipl.-Ing.
Supervisors/Advisors
  • Chladil, Kerstin, Co-Supervisor (external), External person
  • Eichlseder, Wilfried, Supervisor (internal)
  • Leitner, Martin, Co-Supervisor (internal)
Award date1 Jul 2011
Publication statusPublished - 2011

Bibliographical note

embargoed until 31-05-2016

Keywords

  • hard-facing
  • hard faced layers
  • fatigue-wear-life

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