3Cr17Ni7Mo2N, austenitic stainless steel, codename 318, was developed in 1968 by Shanghai Research Institute of Materials, Shanghai No. 5 Iron and Steel Works, Chongqing Steel Works, Sichuan Petroleum Management and Design Institute [TJC STEEL]jointly for the Sichuan gas field natural gas contains more hydrogen sulfide, which causes serious corrosion to the equipment.

 

Component Specification

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 STEEL]	N	0.15~0.22

 

 Mechanical Property

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

 

Material performance:

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 STEEL]medium corrosion resistance.

 

Applications:

The 318 is typically used to manufacture sulfur [TJC STEEL]resistant wellheads, valves, stems, and fasteners for applications where H2S partial pressures exceed 1MPa.