Effect of Heat-Treatment on the Microstructure, Mechanical Properties and Corrosion Behaviour of SS 316 Structures Built by Laser Directed Energy Deposition Based Additive Manufacturing

• DOI: 10.1007/s12540-020-00838-y
• Publication Date: 2020-08-18T08:03:46Z
• Authors: K. Benarji; Y. Ravi Kumar; A. N. Jinoop; C. P. Paul; K. S. Bindra
• Keywords: 0205 materials engineering; 02 engineering and technology

This paper reports investigation on the effect of heat-treatment on the microstructure, mechanical, tribological and corrosion characteristics of laser directed energy deposition (LDED) built stainless steel (SS 316) bulk structures. LDED built SS 316 structures are subjected to solution treatment at 1073 K (HT1073) and 1273 K (HT1273) and reduction in ferrite phase with heat-treatment is observed from microstructure. X-ray diffraction and microstructure shows that the austenite phase is observed at all conditions and reducing ferrite phase intensity is noticed with an increase in heat-treatment temperature. Improvement in the plasticity retaining capacity and reduction in micro-hardness by 72.8% and 6.75% are noticed with heat-treatment, respectively. It is observed that the corrosion rate and specific wear rate increases after heat-treatment. The maximum specific wear rate of 0.19375 × 10–4 mm3/min is observed in the HT1273 sample with wide and deep grooves noticed on the worn out surface of heat-treated samples. The SEM images of wear track is characterized with abrasive wear mechanism for as-built sample, while heat-treated samples shows plastic deformation, followed by spalling effect. The work paves a way to understand the effect of heat-treatment on LDED built SS 316 bulk structures.