150 mm and 170 mm Round Bars of Grade 1.2787 ESR Equvelant To AISI 431 Hardened And Tempered To 950-1050 C Degree Freq
Type 431 Stainless Steel
Hardenable Martensitic Stainless Steel Alloy
Type 431 is a hardenable martensitic stainless steel alloy which has a combination of high tensile and torsional strength - this makes it well suited to shaft manufacture.
The alloy is intended for use in applications requiring good strength and toughness combined with reasonable corrosion resistance. As the alloy offers considerable resistance to saltwater corrosion, it is used widely in marine equipment and systems. Type 431 is easily machined in the annealed state but welding is difficult due to cracking and it is recommended that the material is preheated to improve welding performance.
Key Features:
Type 431 stainless steel is a heat treatable martensitic stainless - the alloy offers high tension and torsional strength and is well suited in the manufacture of shafts. However, welding is poor and the material cannot be easily cold worked.
Technical Assistance
Our knowledgeable staff and resident metallurgists will be pleased to assist you further on any technical topic. Smiths Metal Centres Limited also boasts an in-house UKAS Accredited Testing Laboratory which is unique within the multi-metal and plastic stockholding sector. We believe this underlines our total commitment to quality and our ethos of being the complete service provider.
Typical Applications:
- Marine systems
- Pump & propeller shafts
- Outboard motor drive shafts
- Valve stems
- Aircraft components
- Axles
We offer Type 431 Stainless Steel in round bar, plate, sheet and tube. We provide dedicated processing services throughout the Smiths Group - with more than 30 band saws and a fully automated magazine feed CNC rod blanking line, we can process your material to your exact requirements.
431 STAINLESS UNS S43100
431 stainless 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.
