I am looking for the best available material solution for Oil&Gas industry with occasionally presence of H2S. For now we are using A286 but I am not sure about its H2S resistance. What kind of material you can recommend that is comparable to A286 and is H2S rated?
When dealing with Sour Gas (H2S), the problem is the formation of Sulfuric Acid. Although A286 bolts are very strong, with a min UTS of 130 KSI, they are not particularly resistant to H2SO4 as A286 is an iron based alloy. A high strength and corrosion resistant alloy that you might want to consider would be Inconel fasteners. Depending on the strength requirements of your application, Inconel 625 or 718 bolts might work very well for you. Inconel 718 bolts offer the highest strength option at 185 KSI and Inconel 625 having a min of 120 ksi. Because both are nickel based alloys, they will perform much better than A286 from a corrosion point of view when exposed to sour gas.