The Influence of Vibration on the Microstructure of the Wear-Resistant Layer Made with the Welding Wire MSG-6-GZ-C-60G

Abstract

In the production of steel parts exigent of high durability to abrasive wear at high temperatures and / or corrosive environment, the method is used for the deposition welding with the addition material MSG-6-GZ-C-60G. With this material layer it is made of 55-60 HRC hardness, corrosion and wear resistant, with properties that are kept up to temperatures of 5000 C. There can be manufactured new parts (pressure casting forms, components for dies, molds, etc.), or dynamically and abrasion-torn reconditioned parts may be required. Deposits have been made with wear-resistant layer on the steel 42CrMo4, with and without the generation of vibration during welding. For the samples swing, a device was used with an electrodynamic exciter to generate vibrations with frequencies up to 20 kHz. Vibration tests were performed at a frequency of 50 Hz, because the frequency can be applied in industrial conditions, by means of excitation of electromagnetic or vibration driven motor. There have been registered horizontal and vertical accelerations which lead to changes in the conditions of crystallisation of the melt, respectively the formation of a microstructure with superior features. Microstructures and hardness recorded on specimens welded with and without vibration are comparatively presented. Micrographs which were made demonstrate the favourable influence of the vibration on the quality of the deposited layer and the base material. Whith the vibration with accelerations of ax= 55 m/s2and az= 70 m/s2resulted: much lower deformation of the base material, HAZ - a lower content of residual austenite, in the TZ there was a great interlock of the two materials, in the deposited material the dendritic crystals strongly fragmented and the grain was finished.