C 0.22~0.30 Cr 16.00~18.00 Ni 6.00~8.00
Si 0.80~1.60 P ≤0.035 Mo 2.00~2.50
Mn ≤1.00 S ≤0.30[TJC STAINLESS] N 0.15~0.22
solution heat treatment 1130℃±10℃, holding for 2h, water quenching
strength of extension MPa ≥785
yield MPa ≥420
percentage elongation after fracture % ≥35
reduction of area% ≥40
hardness HRC ≤24
318 is a low cost material developed for hydrogen sulfide corrosion resistance. It can resist hydrogen sulfide uniform corrosion, sulfide stress cracking resistance, hydrogen embrittlement resistance, pitting resistance, reducing [TJC STAINLESS]medium corrosion resistance.
The 318 is typically used to manufacture sulfur [TJC STAINLESS]resistant wellheads, valves, stems, and fasteners for applications where H2S partial pressures exceed 1MPa.