Welding method, filler metal composition and article made therefrom

A method of welding stainless steel components comprising the steps of:

• (a) providing stainless steel components of a desired stainless steel composition;
• (b) austenitizing the stainless steel components to be welded at a temperature of about 1800° F.-2000° F.;
• (c) joining the components by welding, using an arc welding technique and using a filler metal alloy comprising in % by weight:
• up to 0.02% carbon;
• 4.5-5.5% nickel;
• 0.4-0.7% molybdenum;
• 10-12.5% chromium;
• 0.1% copper;
• up to 0.8% manganese;
• up to 0.02% phosphorus;
• up to 0.015% sulfur;
• up to 0.6% silicon;
• the balance being essentially iron and incidental impurities to provide a
• welded assembly;
• and
• (d) tempering the welded assembly at a temperature of about 930° F.-1300° F.

An impeller for use in a compressor for exposure to petrochemical corrosive fluids and low temperature service, said impeller comprising:

• a central hub;
• an outer cover spaced from the central hub;
• a plurality of blades having opposed elongated edge portions wherein a first edge portion of each blade is joined by welding to the central hub of the impeller and an opposed edge portion of each blade is joined by a welding bead to the outer cover of the impeller;
• wherein the blades, hub and cover are made from a type 13Cr-4Ni stainless steel;
• and
• wherein the weld bead joining the blades to the hub and cover has a maximum Rockwell C Hardness (HRC) of 23 and is formed by a filler metal alloy comprising in % by weight:
• up to 0.02% carbon, up to 0.8% manganese, up to 0.02% phosphorus, up to 0.015% sulfur, up to 0.6% silicon, 4.5-5.5% nickel, 0.4-0.7% molybdenum, 10-12.5% chromium, up to 0.1% copper, the balance essentially iron and incidental impurities.