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This study sought to explore the relationship between positive and negative affect and the effects of an intervention on gratitude. We used data from the Psi Beta National Research Project.

In the present work bimetal composite plates of ZERON 100 superduplex stainless steel and ASME SA516-70 carbon steel were produced by explosion welding and submitted to post weld heat treatment for stress relief. The cross section microstructure of the cladded plates was characterized by optical microscopy and scanning electron microscopy and the hardness profile across the weld interface was determined. Residual stress analysis by X-ray diffraction was performed before and after heat treatment on the stainless steel side of the cladded plates. In the as-welded condition, metallography analysis indicated severe plastic deformation at the welded interface and a wavy morphology characteristic of high adhesive strength. Elevated tensile residual stresses were created as a result of the welding process. The heat treatment process applied (6h at 250°C) did not alter hardness at the welded interface nor the residual stress state in the cladded materials.

In the present work, different corrosion resistant materials (AL-6XN superaustenitic stainless steel, ZERON 100 superduplex stainless steel and Inconel 625 Ni alloy) were joined with ASME SA516-70 carbon steel by explosion welding to form bimetal composite plates. The microstructure of cladded plates was characterized by optical and scanning electron microscopy and the hardness variation across the interface was determined by applying Vickers microhardness. The residual stresses generated by the cladding process were determined by X-ray diffraction. All materials adhered well to the ASME SA516-70 base plate and the cladded interface exhibited the wavy morphology usually associated with strong bond strengths. Hardness increased near the interface due to strain hardening caused by plastic deformation and tensile residual stresses were found to develop on all clad metals.

In the present work the explosion welded joint produced between an Inconel 625 alloy and ASTM A516-70 carbon steel sheets was investigated. After welding, the cladded plates were submitted to stress relief annealing at 600 °C for 3 h. The cross section of the cladded plates was examined in both as welded and heat treated conditions by optical microscopy and scanning electron microscopy. The hardness profile across the cladded interface was determined and the residual stress state created as a consequence of the explosion welding process was determined by X-ray diffraction. The experimental results showed that the Inconel 625 alloy adhered well to the ASTM SA516-70 steel, demonstrating the viability of the explosion cladding process for producing bimetal plates of the mentioned alloys. In the as welded condition, metallography analysis indicated severe plastic deformation close to the cladded interface and a wavy morphology characteristic of high bond strength. Elevated tensile residual stresses were created as a result of the welding process and considerable stress relaxation was attained by application of the proposed heat treatment.

Explosion welding is a solid state joining process that allows the manufacturing of corrosion resistant structural composite materials in the form of plates. In the present work, composite bimetal plates of AL-6XN superaustenitic stainless steel and ASME SA516-70 carbon steel produced by welded were studied. Post-weld annealing for stress relief was conducted at 600 °C for 30min and the materials were examined in both the as welded an heat treated conditions. The microstructure of the weld was characterized by optical and scanning electron microscopy and the variation of hardness across the cladded interface was determined by applying Vickers microhardness. The residual stresses generated by the explosion welding process were analyzed by X-ray diffraction using the sin2ψ technique. The cladded interface exhibited a wavy morphology, characteristic of high bonding strength in explosion welds and the variation of hardness was found to be strongly influenced by strain hardening at the cladded interface. Elevated tensile stresses (700 ± 30 MPa) were present after explosion welding. Application of the proposed heat treatment allowed for significant stress relaxation, with a final tensile stress of 90 ± 10 MPa.