Product Code: ICAL09_M1009

Effect of Laser Color Marking on the Corrosion Performance of Stainless Steel
Authors:
Elin M. Westin, Outokumpu Stainless AB; Avesta Sweden
Petri Laakso, VTT Technical Research Center of Finland; Lappeenranta Finland
James Oliver, Outokumpu Stainless AB; Avesta Sweden
Raimo Penttila, VTT Technical Reseach Center of Finland; Lappeenranta Finland
Presented at ICALEO 2009

With the continuous and rapid development of laser marking technology, the field of applications increases. The method can be used to write text on stainless steel and has even been shown to improve the corrosion performance of the surface. In this work, the suitability of laser marking stainless steel is studied for writing product data on the outer surface of inline tubes during production. Generally, thermal oxidation of a stainless steel surface will deteriorate its pitting resistance and, even though corrosive media may be transported inside the tubes, pitting attack from the outside can cause failures. Three commercial stainless steels, austenitic 316L (EN 1.4404 / UNS S31600) and duplex grades LDX 2101 (EN
1.4162 / UNS S32101) and 2304 (EN 1.4362, UNS S32304), were laser marked using two different parameter settings that resulted in two different oxide colors. The oxide composition and thickness were studied with glow discharge optical emission spectroscopy (GDOES) and the effect of surface appearance on pitting corrosion resistance was determined using ASTM G150. It is shown that the oxide thickness affects the corrosion performance.