Weldability of Stainless Steel 440C Round Bars

Stainless steel 440C round bar is a high-carbon martensitic stainless steel. 440C Martensitic steel round bars are commonly used in applications where high strength and moderate corrosion resistance is required.

Martensitic stainless steel 440C is magnetic and can be hardened by heat treatment. The high carbon content in 440C provides high hardness and strength. Despite this carbon content, the chromium content is sufficient to retain its stainless characteristics.

Weldability of Stainless Steel 440C Round Bars

Because of its high-hardness capability, this steel is seldom welded. However, if welding is necessary, the parts should be preheated and maintained at about 500°F, welded, and then immediately given a 6-8 hour anneal at 1350/1400°F with a slow furnace cool. The parts should not be allowed to cool below 500°F between welding and annealing. High welding heat inputs should be used. To obtain mechanical properties in the weld similar to those in the base metal, welding consumables of like composition should be considered. Otherwise AWS E/ER309 might also be considered.

Martensitic Steel 440C Features

Attain the highest hardness of any stainless steel, when heat-treated

Highest carbon content of 400 series stainless steels

Martensitic Steel 440C Heat Treatment:

Hot Working: Preheat to 1400/1500°F, then heat slowly and uniformly to 1900/2100°F. Do not forge below 1750°F, and reheat as often as necessary. Furnace cool slowly. Anneal after forging; cool to room temperature before annealing.

Annealing: Heat to 1550 - 1600°F, slow cool in furnace. Brinell hardness should be approximately 223.

Hardening: Heat to 1850/1950°F. Quench in warm oil or air. Do not overheat. Temper between 300 - 800°F depending on desired hardness. Temper immediately after quenching.

Cold Working: If annealed for maximum softness, this steel can be moderately cold formed or headed.

Stainless Steel 440C Round Bars Applications:

Valve Seats

Surgical Instruments

Bearings

Bushings

Nozzles

Structural Aircraft Parts