Effect of hybrid manufacturing (am-machining) on the residual stress and pitting corrosion resistance of 316L stainless steel

Author(s)

Bordinassi, Ed Claudio ; Mhurchadha, Sinead Ui ; Seriacopi, Vanessa ; Delijaicov, Sergio ; Giampietri Lebrao, Susana Marraccini ; Thomas, Ken ; Batalha, Gilmar Ferreira ; Raghavendra, Ramesh

• Document type: Journal article
• Source: Journal of the Brazilian Society of Mechanical Sciences and Engineering; v. 44, n. 10, p. 16-pg., 2022-10-01.

Abstract

The use of additive manufacturing (AM) has grown exponentially in recent years and has many advantages, including feasibility, over other conventional processes in many current applications. The use of a second process, for example, machining, improves the surface finish and in this case, the use of two processes is known as hybrid manufacturing. Heat treatments are often performed on parts generated by the AM process, mainly to relieve the residual stresses generated, but for some materials, this can decrease the pitting corrosion resistance of the parts. The objective of this study is to analyze the effect of hybrid manufacturing (AM + machining) on residual stresses and pitting resistance corrosion, which can bring advantages to piece properties without the use of heat treatment. 316L stainless steel parts are generated by direct laser metal sintering (DLMS), with subsequent milling using a complete factorial planning for the design of the experiments. The cutting speed, feed rate, cutting depth, use of the cutting fluid and laser power in the DLMS process are all varied. Residual stresses are measured by X-ray diffraction and the blind hole method, with polarization curves raised by a potentiostat. The results show that it is possible to reduce the residual surface stresses in the parts, even for compressive stresses, and to improve the pitting corrosion resistance, when compared to the part without milling, depending on the cutting parameters used. (AU)

• FAPESP's process: 20/10653-5 - Assessments of porosity effects on mechanical behavior and scratch tests onto the AISI 316L steel obtained using additive manufacturing (DMLS) and sintering (SPS)
• Grantee: Vanessa Seriacopi
• Support Opportunities: Regular Research Grants
• FAPESP's process: 20/09163-3 - Multi-user equipment approved in grant 2019/25707-6: scanning electron microscope
• Grantee: Vanderlei Cunha Parro
• Support Opportunities: Multi-user Equipment Program