Fatigue behavior of laser clad round steel bars

Abstract

Laser cladding is an overlay welding method to manufacture high performance, fusion bonded metal, and metal matrix composite coatings on metallic substrates with low dilution. Owing to steep thermal gradients, rapid solidification, and possible mismatch in coefficients of thermal expansion between the coating and the substrate, laser cladding induces large tensile residual stresses in coating layer, potentially affecting the service life of clad component under external load-induced stresses. In this study, four-point bending and torsion fatigue tests were conducted on relatively large round laser clad steel bars to determine the effect of laser cladding on fatigue strength. Quenched and tempered 42CrMo4 steel clad with Inconel 625 and S355 structural steel clad with Stellite 21 were subjected to various stress levels for relatively large number of cycles with and without postweld heat treatment (PWHT). The results indicated that Stellite 21 decreased the fatigue life of S355 at all the applied loads, whereas Inconel 625 increased the fatigue life of 42CrMo4 at high loads but decreased at low loads. Applied PWHT did not show any positive influence on fatigue life.

Influence of interlayer time on the microstructural state of CoCrMo coatings applied by selective laser melting on an iron-based substrate for different numbers of layers

“…To apply CoCrMo coatings to the steel substrate surface, different depositing processes can be used, such as Metal Inert Gas MIG [3], laser cladding [4][5][6] or spraying processes [4]. During the CoCrMo alloy coating processes, iron dilution from substrate to coating can occur.…”

Influence of iron dilution on plastic deformation mechanisms in cobalt-based alloys: Consequence of phase transformations on tribological behavior

“…Cobalt-based alloys are often used as thick coatings on steel substrate to improve surface properties, such as wear, oxidation, and corrosion resistance [1,2]. To produce CoCrMo coatings on a steel substrate sur-face, different depositing processes can be used, such as Metal Inert Gas MIG [3], laser cladding [4][5][6] or spraying processes [4]. Depending on the input energy densities involved in coating processes, iron dilution from substrate into coatings of the CoCrMo alloy can occur [3,4].…”

Interface Characteristics and Properties of a High-Strength Corrosion-Resistant Stainless Steel Clad Rebar

“…Tuominen et al applied the laser cladding method to fabricate two different kinds of round SSC rebars. The first one was made by the cladding layer of St21 and substrate metal of S355, and the other was made by the cladding layer of In625 and the base metal of 42CrMo4 [11].…”