Abstract
In the investigation at hand, sheets of ferritic and pearlitic grey cast iron with spheroidal graphite are welded using a fiber-laser. The influence of varying laser power and welding speed on the macroscopic characteristics of the weld seam and crack formation are analyzed and discussed. Substantial crack formation with crack densities of up to 2.93 cm−1 are found. Furthermore, hardness measurements are conducted to evaluate the formation of brittle phases within the weld metal and heat-affected zone. Peak hardness values of up to 860 HV0.3 and 975 HV0.3 are identified in EN-GJS-400-15 and EN-GJS-700-2, respectively. Subsequently, a proposition on the dependence of crack formation on weld seam width is given. Furthermore, the influence of nickel-containing filler material on the microstructure, crack formation and hardness is studied. It can be derived from the results that laser-beam welding of grey cast iron with spheroidal graphite requires further research in order to achieve crack-free weld seams and hinder the formation of undesirable, brittle phases.
Highlights
In light of rising efforts to combat climate change, new practices must be implemented to reduce emissions and increase energy efficiency
In order to analyze the microstructural evolution, crack formation and hardness of such an approach, both materials were welded with nickel filler material in form of a foil that was inserted between the two sheets at the abutting edges
High-energy laser beam welding (LBW) of grey cast iron with spheroidal graphite leads to substantial crack formation on top of the weld seam with an increase of welding speed, reaching crack densities of up to 2.93 cm−1 and 2.44 cm−1 in EN-GJS-400-15 and EN-GJS-700-2, respectively
Summary
In light of rising efforts to combat climate change, new practices must be implemented to reduce emissions and increase energy efficiency. Reliance on bolted connections is common because during welding, high carbon contents promote the growth of hard and brittle microstructures such as martensite and ledeburite [2] The impact of these microstructures is seen in the reduction of tensile strength and loss of ductility. Through the utilization of an integrated heat treatment during electron beam welding of grey cast iron, they reported a significant reduction of crack density, pores and hardness increase within the WM and HAZ [8,9,10]. In order to manipulate the thermal cycle during welding, Vollmer et al [13] used electromagnetic induction to impose pre- and post heat-treatment on grey cast iron specimens welded by fiber-laser and reported a reduction of crack formation as well as hardness. The authors of the present publication seek to systematically investigate the influence of process parameters on the microstructural evolution, crack formation and hardness of grey cast iron during LBW
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
