GRADE F6NM

Stainless, Duplex, Super Duplex

UNS S41500: ASTM A182

GENERAL SCOPE

F6NM is a martensitic stainless steel. The additions of Nickel and Molybdenum, which gives it excellent sub zero notch ductility, superior to other standard 13 Cr, 410 and 420 Mod martensitic stainless steels.

F6NM steel is air hardening, with little danger of thick sections cracking during heat treatment.

In addition to limiting the maximum hardness allowed to 23 HRC max, NACE MR0175 imposes heat treatment temperature restrictions.

The weldability and corrosion resistance of F6NM are also excellent, being extensively used in the manufacture of Valve Bodies, Flanges, Seats, Gates, and Tubulars.

ASTM A182 specifies a minimum 0.2 PS value of 95 KSI. This NACE approved grade is limited to 75 KSI because of the hardness restriction. However, with targeted cast analysis and Howco’s heat treatment control, a higher yield strength of 85 KSI can be achieved while still meeting the NACE hardness constraints.

CHEMICAL COMPOSITION

CSiMnPSCrNiMoFe
Min..0.50..11.503.500.500.00
Max0.050.601.000.0300.03014.005.501.000.00

MECHANICAL PROPERTIES

Condition: Hardened and Double Tempered
U.T.S95 KSI Min(655 N/mm2)
0.2% Proof Stress75 KSI Min(517 N/mm2)
Elongation18 %
Red of Area35 %
CVN Impacts @ -60°C (-75°F)40 Joules(30 ft-lbf)
NACE MR0175 limits the supply hardness to 23 HRC max.