Alloy 416 is a martensitic free-machining chromium steel alloy and is generally considered the first free-machining stainless steel. It has the highest machinability of any stainless steel, about 85% of free-machined carbon steel. Martensitic stainless steels are designed to be heat-hardenable and corrosion-resistant.
Although 416 stainless steel and other martensitic stainless steels are not as durable as austenitic or ferritic stainless steels, they still exhibit good corrosion and oxidation resistance and high strength in hardened and tempered conditions. Alloy 416HT is easy to machine, always magnetic, and has low friction properties that reduce wear and seizing.
416 stainless steel is commonly used in parts that are extensively machined and require the corrosion resistance of 13% chromium stainless steel. Applications where Alloy 416 is commonly used include: electric motors; nuts and bolts; water pumps; valves; automatic screw machine parts; washing machine components; studs; gears.
Demonstrates corrosion resistance to natural food acids, waste products, alkaline and neutral salts, natural water and most atmospheric conditions, with poor corrosion resistance of austenitic stainless steels and 17% chromium ferritic alloys such as those of Alloy 416 High-sulfur, free-cutting grades not suitable for marine or other chloride exposure, achieve maximum corrosion resistance in hardened conditions with a smooth surface finish.
Extends fairness to 1400 F (760 ò C) in intermittent service and up to 1247 F (675 C) in continuous service
If maintenance of mechanical properties is important, use at temperatures above the corresponding tempering temperature is not recommended
In terms of welding characteristics of 416 stainless steel, the weldability is poor, if welding requires the use of alloy 410 low hydrogen electrodes, preheated to 392 to 572°F (200-300°C). Immediately anneal or reharden, or stress relieve at 1202 to 1247°F (650 to 675°C). In terms of machinability, it has excellent machinability, and the best machinability is in the subcritical annealed state.
