Investigating the effect of heat treatment on the microstructure, mechanical properties andcorrosion resistance of additively manufactured ۳۱۶L

Selective laser melting (SLM) is an additive manufacturingtechnique currently utilized by several industries, such aspower plant industries, for its ability to produce complexnear-net-shaped components with minimal material waste,which also reduces the production lead time. The presentarticle investigates the microstructural features, mechanicalproperties, and corrosion resistance of an additivelymanufactured stainless steel ۳۱۶L. Four types of sampleswere characterized: as built, annealed at ۸۸۵°C (HT-۸۸۵),annealed at ۱۰۵۰ °C (HT-۱۰۵۰), and hot isostatic pressed(HIP). Microstructural analyses reveal the commonproperties in SLM-built parts, for instance, melt pools, trackboundaries, columnar elongated grains along the buildingdirection, and epitaxially grown grains. The characteristicswere eliminated in higher post-treatment temperatures; somerecrystallization and annealing twins may also occur. Tobetter understand the part's mechanical properties, the tensiletest was performed on the samples, which shows that yieldand ultimate tensile strength have decreased after heattreatment. To achieve a better point of view about thecorrosion properties, wrought-۳۱۶L, and SLM-۳۱۶L beforeand after heat treatment were compared. The investigationrevealed superior corrosion resistance of SLM-۳۱۶Lcompared to wrought-۳۱۶L, which is yet another merit of theSLM method that designers should consider when choosingthe production process.