UKAEA-CCFE-PR(20)126

Selective laser melting of precipitation-hardened martensitic stainless steels: a review

Martensitic stainless steels have been widely used in industries due to their high strength and good corrosion resistance performance. Precipitation-hardened (PH) martensitic stainless steels are featured by their very high strength compared with other stainless steels, around 3-4 times of the strength of austenitic stainless steels such as 304 and 316. However, the poor workability due to the high strength and hardness induced by precipitation hardening limits the extensive utilization of PH stainless steels as structural components of complex shapes. Selective laser melting (SLM) is an attractive additive manufacturing technology, which not only exhibits the advantages of producing complex and precise parts with a short lead time, but also avoids or reduces the subsequent machining process. In this review, the microstructure of martensitic stainless steels in as-built state, effects of process parameters, building atmosphere and heat treatments on the microstructures are reviewed. Then the characteristics of defects in the as-built state and the causes are specifically analyzed. Afterwards, the effect of process parameters and heat treatment conditions on mechanical properties are summarized and reviewed. Finally, the remaining issues and suggestions on future research on SLM of martensitic precipitation-hardened stainless steels are put forward.

Collection:
Journals
Journal:
Metals
Publisher:
MDPI (Multidisciplinary Digital Publishing Institute)