Effect of Crystallographic Orientation on the Pitting Corrosion Resistance of Laser Surface Melted AISI 304L Austenitic Stainless Steel

The localized corrosion behavior of laser surface melted 304L austenitic stainless steel was studied by potentiodynamic polarization test. The extent of improvement in corrosion resistance was governed by the preferred orientation and the percentage of delta ferrite present on the surface of the laser melted sample. It was established by orientation imaging microscopy that the highest pitting potential value was obtained when grains were oriented in the most close- packed [101] direction compared to the random distribution of the base metal and other laser surface melted samples oriented in [001] direction. The sample with lower percentage of ferrite had good pitting resistance.

Authors:

• S. Krishnan
• J. Dumbre
• S. Bhatt
• Esther T. Akinlabi
• R. Ramalingam

Keywords:

• Crystallographic orientation
• Ferrite percentage
• Laser melting
• Pitting corrosion
• 304L SS.

References:

[1] O. V. Akgun, O. T. Inal, M. L. Lovato, and T. R. Jervis, "Effect of laser
surface melting on tensile properties of type 304L stainless steel,"
Scripta Metallurgica et Materialia,Vol. 27, no.2, pp. 191-194, July 1992.
[2] A. Conde, I. Garcia, J. J. de Damborenea, "Pitting corrosion of 304
stainless steel after laser surface melting in argon and nitrogen
atmospheres," Corrosion Science, Vol. 43, pp. 817-828, 2001.
[3] T. M. Yue, J. K. Yu, H. C. Man,"The effect of excimer laser surface
treatment on pitting corrosion resistance of 316LS stainless steel,"
Surface and Coatings Technology, Vol. 137, pp.65-71,2001
[4] P. H. Chong, Z. Liu, X. Y. Wang, P. Skeldon, "Pitting corrosion
behaviour of large area laser surface treated304L stainless steel," Thin
Solid Films,Vol. 453 , pp.388-393, 2004.
[5] A. Shahryari, J.A. Szpunar , S.Omanovic, " The influence of
crystallographic orientation distribution on 316LVM stainless steel
pitting behaviour," Corrosion Science, Vol. 51 pp.677-682, 2009.
[6] B. Ravi Kumar, R.Singh, B. Mahato, P. K. De, N. R. Bandyopadhyay,
D. K. Bhattacharya, " Effect of texture on corrosion behaviour of AISI
304L stainless steel," Materials Characterization,Vol. 54 pp.141- 147,
2005.
[7] X. Y. Wang, Z. Liu, P. H. Chong, "Effect of overlaps on phase
composition and crystalline orientation of laser-melted surfaces of 321
austenitic stainless steel," Thin Solid Films, Vol. 453, pp.72-75, 2004.
[8] W. Hofmeister, M. Wert, J. Smugeresky, J.A. Philliber, M. Griffith, and
M. Ensz, "Investigating Solidification with the Laser-Engineered Net
Shaping (LENSTM) Process,"JOM-e,vol.51,no.7.
http://www.tms.org/pubs/journals/jom/9907/hofmeister/hofmeister-
9907.html
[9] A. F. Padilha, C. F. Tavares; M. A. Martorano, " Delta Ferrite Formation
in Austenitic Stainless Steel Castings," Materials Science Forum, Vol.
730-732, pp 733-738, 2013.
[10] E.H. Dix, "Corrosion of light metals," American Society of Metals,
15,1946.