Investigation of the residual stress distribution in repairs in H13 steel by friction hydro pillar processing

Abstract

The distribution of residual stresses (RS) in repairs generated by Friction Hydro-Pillar Processing (FHPP) in AISI H13 was investigated. Three axial force levels, with consequent different deposition rates, were applied to replicate possible repaired conditions. The contour (CM) and X-ray diffraction (XRD) methods were employed for RS analysis in samples that were also evaluated through metallography, microhardness analysis, micro-tensile and Charpy testing. CM produced 2D maps of the RS in the joints, showing symmetrical distributions around the welded rod for all welded conditions. Other common features for all conditions were the maximum level of compressive RS, which was found in the TMAZ of the rod, and the maximum tensile residual stress, which was found near the HAZ of the base block. There was good agreement between the RS measurement techniques. Mechanical tests show similar tensile resistance for all conditions and an apparent increase in toughness at higher force levels.

Investigation of Friction Hydro-Pillar Processing as a Repair Technique for Offshore Mooring Chain Links

“…Other authors revealed this same pattern, even with other materials or processes. Amavisca et al [18] noticed it when applying the counter method and the X-ray method in FHPP. Roy et al [37] and Yiet al [34] found it in all directions in the clad process.…”

“…Figure 8 presents the full width at half maximum (FWHM) of the neutron diffraction data for as-repaired conditions in the three directions and a hardness profile at 4 mm from the surface. As used by Yi et al [34] and Amavisca et al [18], the FWHM results were displayed with a relevant hardness curve to provide a better comprehension. Furthermore, as commented by Chen et al [35], hardness is a result of elasticity, plasticity, work hardening capability, mechanical strength, and toughness data, where angular diffraction is indicative of strain hardening, micro-strain, dislocation density, and grain refinement.…”

“…From that point towards the BM, the values decreased until reaching the compressive As a friction solid-state process, it involves high levels of plastic deformation, although the temperature reached is considered low (below the melting point) compared to fusion processes. Nevertheless, residual stresses (RSs) are associated with inhomogeneous thermal distribution, plastic deformation, and phase transformations [3,18]. This aspect is extremely relevant since the RS has various effects on the performance of materials, such as fracture toughness, fatigue life, and stress corrosion cracking.…”

“…The PWHT relived the compressive stress setting between 275 and 380 MPa, representing 16% of the hoop maximum values. Amavisca et al [18] used X-ray diffraction to analyze AISI H13 steel FHPP welds with PWHT. The authors measured a compressive field in the hole/stud interface with tensile peaks near the heat-affected zone (HAZ) of the BM.…”

Continuous repair of groove damages using solid-state friction rolling additive manufacturing method

“…Vicharapu et al [17] and Landell et al [18] reported the microstructure evolution and material flow of the taper holes damages repaired by friction hydro-pillar process. Amavisca et al [19] investigated the distribution of residual stresses generated by friction hydro-pillar repairing of AISI H13. In these methods, the tool head cannot transverse to achieve filling material and repairing the groove damage simultaneously.…”