Laser metal deposition of multi-track walls of 308LSi stainless steel

ABSTRACT

Laser metal deposition using wire feeding system is increasingly becoming known as a process for making engineering components from the scratch. The process quality determines the end properties of the components hence, their lifetime performances in the service environments. In this study, single tracks and multiple tracks (walls) of AISI 308LSi on AISI 304 substrate were laser deposited using lateral wire feeding system. The microstructures of the deposited tracks were examined using optical microscopy and scanning electron microscopy. The macrohardness at different stages of the built walls was determined using Vickers hardness tester, while the ultimate tensile strength of the walls was investigated according to ASTM E8M-13 standard. The microstructure of the walls revealed nearly vertical columnar dendrites growing perpendicularly to the horizontal. The macrohardness of the deposited walls is within 167–194 HV but decreased from the bottom layer to the top layer. The tensile strength of the walls which ranges between 474 and 525 MPa depends on the wall building directions.

KEYWORDS:

• Deposition
• hardness
• laser
• microstructure
• stainless
• steel
• strength
• tensile
• wall
• wire