Dear RV_DMG,
I understand your concern behind this question, many people find it difficult for selecting stainless steel grade while applying stainless steel coating. I try to make it little easy & explanatory here :-
All grades of stainless steel are good for anti-corrosion & anti wear properties while applying reclamation coating works, only differentiation of characteristics of each grade matters for this selection.
300 series of SS grades are categorized into austenitic stainless steel which is more good for protecting corrosion failures.
SS 304 is mostly used for several application with carbon % of around 0.08% & commonly it is called as 18/8 steel which means it contains 18% chromium & 8% nickel.
SS 316; which is commonly called as 18/10 i.e. 18% chromium & 10% nickel. Due to addition of molybdenum this grade is even better for anti-corrosion properties specially resistance to pitting & crevice corrosion in chloride environments. Most of marine & petrochemical coating applications use this grade.
SS 316L is nothing but SS 316 grade only, it contents even lesser amount of carbon i.e. <0.03% which is even stronger for corrosion resistance properties. L stand for low carbon percentage.
SS 321; with addition of Titanium & Niobium becomes good resistance of inter granular corrosion for high temperature application up to 900 degree centigrade. This is very rarely used grade for thermal spray application only few of the power plant applications choose this grade.
SS 420 is high carbon steel with chromium content of min. 12%. This grade of SS is hardest among all above; 50 HRC. If gives a very good surface finish if grinded/lapped after spray, this finished surface provide good corrosion resistance. Common application of this grade in industry is reclamation of shafts.
I think I was able to make my all points clear. If you need any further information on any of these wires you can contact me anytime, as I supply all types of metal spray wires with test certificates.
Regards
Harish Dhanadiya
Parat Technologies
India
info@parattech.com
(01-09-2015, 06:06 PM)RV_DMG Wrote: Hello,
Arc spray is very famous process these days & most of rebuilding & corrosion protection application I have read in several journals they suggest for Stainless steel grades 420, 316, 316L, 321, 304. I have big question how to select among these grades for particular application? is there any thumb rule for this selection? a thought clarification will be very beneficial for me to understand this.
Please help!
Regards