347 Stainless Steel Forgings UNS S34700

Type 347 stainless steel is a columbium/tantalum stabilized austenitic stainless steel. Similar to 321 stainless, it has good intergranular-corrosion resistance compared to typical 18-8 type alloys. With the addition of columbium and tantalum, which have a stronger affinity for carbon than chromium, the carbides will tend to randomly precipitate at the grain boundaries rather than form continuous patterns.

Applications: 347 stainless steel is widely used in aircraft exhaust, collector rings, expansion joints and in high temperature chemical processing

347 is resistant to atmospheric conditions and should be considered for applications requiring intermittent heating between the temperatures of 800f (427c) and 1650f (899c)

Chemistry Analysis

Carbon 0.08% Manganese 2.00%
Phosphorus 0.045% Sulfur 0.030%
Silicon 1.00% Chromium 17.00 – 19.00%
Nickel 9.00 – 13.00% Columbium/Tantalum 0.40 – 0.90%
Iron 63.95 – 70.44
Phosphoric Acid Moderate Acetic Acid Moderate
Sodium Hydroxide Moderate Sea Water Restricted
Salt Spray Good Nitric Acid Good
Sulfuric Acid Moderate Humidity Excellent
Sour Oil/Gas Moderate

Corrosion Resistance for 347 Stainless

The following table is for reference only, many factors can affect the corrosive resistance, a corrosion test for each application should be applied.

Heat Treatment
Heat to 1850/2000 F (1010/1093c) and quench in water. Brinell hardness approximately 150.
Cannot be hardened by heat treatment, it can only be hardened through cold working.
If temperature during use is expected up to 1600 degrees, stabilizing between 1550/1650f (843/899c) can be used for optimum intergranular corrosion.
When machining 347 its chip is tough and stringy, use rigid tooling with heavy cuts to prevent work hardening.
AMS 5646 ASTM A182 ASTM A276 ASTM A314 ASTM A473 QQS 763 ASME SA182 EN10204 DIN3.1B
Shapes Manufactured:
Flat Bars, Square Bars, Round Bars, Rings, Hollows, Discs, Blocks and special Shapes. Send us a drawing to see how we can save you material and Machining time!

The information in this data sheet is for information only and should not be used for engineering.

347 Typical Room Temperature Mechanical Properties
Stainless Annealed 1900f (1038c) 1” rd bar
0.2% Yield Strength Ultimate Tensile Strength % Elongation in 2” (50.8mm) % Reduction of Area Brinell Hardness Izod Impact Strength
ksi Mpa ksi Mpa Ft-lb J
37 255 90 621 50 65 150 110 149