Wroughtable, chromium-bearing, cobalt-based alloys with improved resistance to galling and chloride-induced crevice attack

A chromium-bearing, cobalt-based alloy amenable to wrought processing with improved resistance to both chloride-induced crevice corrosion and galling, the alloy having a critical crevice temperature of at least 100° C. when tested according to ASTM Standard G48, Method D, and a root mean squared roughness not greater than 1.7 microns when subjected to a galling test in which a pin of diameter 15.9 mm/0.625 in. is twisted against a stationary block of thickness 12.7 mm/0.5 in. ten times through an arc of 121°, using a hand-cranked, back-and-forth movement and a load of 2722 kg/6000 lb. applied by means of a tensile unit in compression mode, plus a greased ball bearing seated on a female cone machined onto the top of the pin, comprising:

• up to 3.545 wt. % nickel;
• 0.242 to 0.298 wt. % nitrogen;
• 22.0 to 30.0 wt. % chromium;
• 3.0 to 10 wt. % molybdenum;
• up to 5.0 wt. % tungsten;
• 1.71 to 7 wt. % iron;
• 0.05 to 2.0 wt. % manganese;
• 0.05 to 2.0 wt. % silicon;
• 0.02 to 0.11 wt. % carbon;
• 0.005 to 0.205 wt. % aluminum;
• and
• cobalt plus impurities as the balance.