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431 Stainless UNS S43100

431 was formulated to provide better corrosion resistance and toughness in a quench- hardenable, stainless steel. It maintains good strength and corrosion resistance and hardness, in temperatures from -100 to 1200 degress f (-73/ 650c). It has the best corrosion resistance of the conventional martensitic stainless grades.

Applications: 431 stainless is widely used in highly stressed aircraft components, valves, also pump and pump shafts.

Chemistry Analysis
Carbon 0.20% Manganese 1.00%
Phosphorus 0.040% Sulfur 0.030%
Silicon 1.0% Chromium 15.00 - 17.50%
Nickel 1.25% - 2.50% Iron Balance

Corrosion Resistance

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

Phosphoric Acid Restricted Acetic Acid Restricted
Sodium Hydroxide Moderate Sea Water Restricted
Salt Spray Moderate Nitric Acid Good
Sulfuric Acid Restricted Humidity Good

Heat Treatment

Annealing: typical Heat uniformly 1200/1250f (650/677c) remove from furnace and cool in air. Brinell hardness expected approximately 270. This is the best condition for overall machining.

Hardening: Heat 1800/1950f (982/1066c) soak at heat, quench in oil. You may also harden in air.

Tempering: In the range of 700/1050f (371/565c), to achieve desired mechanical properties. Soak at hest for at least one hour, longer for larger pieces and cool in air.

Typical Room Temperature Tensile Properties

Hardened at 1800f (982c) and oil quenched, followed by tempering at indicated temperature and air cooled.
Temper Temperature Yield Strength Ultimate Tensile Strength % Elongation in 2" {50.8mm} Brinell Hardness % Reduction of Area Charpy V-notch
F C ksi Mpa ksi Mpa ft-lb J
annealed   95 655 125 655 20 280 55 50 68
500 280 149 1027 196 1365 16 415 55 40 76
700 371 163 1123 202 1393 16 429 55 25 34
900 482 174 1200 204 1407 16 415 51 12 16
1100 593 115 793 140 965 19 302 57 48 65
1300 649 99 683 129 889 20 269 60 51 69
Hardened at 1900f (1038c) and oil quenched, followed by tempering at indicated temperature and air cooled.
Temper Temperature Yield Strength Ultimate Tensile Strength % Elongation in 2" {50.8mm} Brinell Hardness % Reduction of Area Charpy V-notch
F C ksi Mpa ksi Mpa ft-lb J
annealed   95 655 125 655 20 280 55 50 68
500 280 148 1020 193 1331 17 388 40 52 71
700 371 145 1000 188 1282 21 388 53 60 61
900 482 156 1076 200 1379 18 415 62 42 57
1100 593 113 779 150 1034 18 321 55 32 43
1300 649 98 676 140 965 18 263 53 45 61
Machinability:
431 in the annealed condition can gall and build up on the cutting tool which can result in poor finishes.
Specifications:
AMS 5628 ASTM A276 ASTM A314 ASTM A479 QQS 763 PWA LCS 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.


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