The Super 13 Chrome alloys, UNS S41426 and HP-2, are quenched and tempered martensitic stainless steels intended for corrosion resistance in sweet (CO2) and mildly sour (H2S) environments with moderate chloride content up to 350°F.
Super 13 Chromes offer improved mechanical properties and increased resistance to the effects of CO2 , H2S, chlorides, pH, and temperatures when compared with standard 13 Chrome. The higher strength and temperature resistance, relative to 13 Chrome L80, allow their use in deeper wells with high pressure and high temperature (HPHT) conditions, as downhole tubular components, packers, and other subsurface equipment. Super 13 Chromes also provide increased resistance to H2S and chlorides relative to Modified 13 Chrome, allowing for use in mild sour environments.
UNS S41426 is included in NACE MR0175/ISO15156 Table A.19, which provides a recommended limit of 1.5 psi partial pressure H2S. API 5CRA/ISO13680 classifies it as Group 1, Category 13-5-2 alloy acceptable for sour service, in the 95 ksi yield strength condition.
Per API 5CRA Table A.2
Made by electric furnace (EF) or basic oxygen furnace (BOF)
Manufactured by traditional hot tube manufacturing processes
Quenched and tempered
Specified Mechanical Properties
API 5CRA / ISO 13680 Group 1 Category 13-5-2
Yield Strength ksi
Tensile Strength ksi
NACE MR0175/ISO 15156 H2S Sour Service Limits
Function of specimen size
H2S ≤ 1.5 psi, pH ≥ 3.5
110 Grade not recommended for sour service
*Non-standard mechanical properties and grades are made available upon agreement.