What is 254 SMO®?
254 SMO® is a stainless steel was initially created to utilize in seawater and other aggressive chloride-bearing situations. This grade includes a very high end austenitic stainless steel; mainly comprised within 17.5% ل 18.5% nickel, 19.5% و 20.5% الكروم, 6% ل 6.5% molybdenum and .18% ل .22% nitrogen.These particular levels of Cr, في, شهر, and N in this “super austenitic” chemical makeup allow 31254 to join impact toughness resistance to corrosion cracking, with pitting and crevice corrosion resistance.The result is strength of almost double that of 300 series stainless steels.
UNS S31254 is treated as a “6% Moly” grade because of the molybdenum content; the 6% Moly family has the ability to withstand high temperatures and keep up strength under volatile conditions. This grade has surpassed its unique expectation and covered into many different industries demonstrating helpfulness owing to its high level of molybdenum amount other elements, which allows 31254 to be utilized effectively as a part of different applications such as flue gas desulfurization and chemical environments.
254 SMO® Products Form
- دائري, Square, سداسي الزوايا ,قضبان مسطحة & Wires
- سلس / مواسير ملحومة
- سلس / الأنابيب الملحومة
- حار & أطباق مدرفلة على البارد & أوراق
- قضبان مزورة
- الشفاه المزورة
- Butt-Weld Pipe Fittings
- Socket-Weld/Forged Pipe Fittings
- Machined Components
- تركيبات ضغط الطويق
- Welding Consumables
- Common Manufacturi
Applications for 254 SMO®
1) Ocean: marine structures in the sea environment, seawater desalination, marine aquaculture, seawater heat exchange, إلخ.;
2) Environmental Protection: flue gas desulfurization device for thermal power generation, wastewater treatment, إلخ.;
3) Energy: atomic power generation, comprehensive utilization of coal, and ocean wave power generation.;
4) Petrochemical Industry: refining, chemical equipment;
5) Food: salt making, soy sauce brewing, إلخ.;
6) High concentration chloride ion environment: paper industry, various bleaching devices;
7) Others.
هquivalents of 254 SMO®
STANDARD | نحن | WERKSTOFF NR. | أفنور | في | هو | SIS | GOST |
SMO 254 | S31254 | 1.4547 | Z1 CNDU 20.18.06Az | X1CrNiMoCuN20-18-7 | - | 2378 | - |
تعبير ranges for 254 SMO®
% | ج | سجل تجاري | مينيسوتا | شهر | ن | في | ص | و | س |
254 SMO | 0.02 الأعلى | دقيقة: 19.5 الأعلى:20.0 | 1.00 الأعلى | دقيقة: 6.0 الأعلى: 6.5 | دقيقة: 0.18 الأعلى: 0.20 | دقيقة: 17.5 الأعلى: 18.0 | 0.03 الأعلى | 0.80 الأعلى | 1.01 الأعلى |
الخصائص الميكانيكية
Properties | Metric | Imperial |
Tensile strength | 680 الآلام والكروب الذهنية | 98600 psi |
Yield strength | 300 الآلام والكروب الذهنية | 43500 psi |
Modulus of elasticity | 195 المعدل التراكمي | 28300 ksi |
Shear modulus | 75 المعدل التراكمي | 10900 ksi |
Poisson’s ratio | 0.30 | 0.30 |
Elongation at break | 50 % | 50 % |
صلابة, برينل | 210 | 210 |
الخصائص الفيزيائية
Units | Temperature in °C | |
كثافة | 8.0 g/cm³ | Room |
حرارة نوعية | 0.12 Kcal/kg.C | 22° |
Melting Range | 1320 – 1390 درجة مئوية | – |
Modulus of Elasticity | 195 KN/mm² | 20° |
المقاومة الكهربائية | 85 µΩ.cm | Room |
Coefficient of Expansion | 16.0 µm/m °C | 20 – 100° |
توصيل حراري | 14.0 W/m °K | 20 ° |
المقاومة للتآكل
- Excellent resistance to pitting and crevice corrosion due to its high chromium, molybdenum, and nitrogen content
- Has a very low carbon content, which means there is very little risk of carbide precipitation during heating
- Possesses very good resistance in water containing chlorides, therefore, it is suitable for use in seawater as it can be exposed to it for prolonged periods without suffering from crevice corrosion
المعالجة الحرارية
Stainless steel grade 254 SMO™ does not respond to heat treatment. Hardening is possible only through cold reduction.
التلدين
2100-2200 F (1149-1204 ج), followed by a water quench.
Hardening
This alloy does not harden by heat treating. High properties might just be acquired through cold reduction
Hot Working
While cold forming is recommended wherever feasible, forging, upsetting and other operations can be performed at 1800-2100 F. Temperatures above this range will cause scaling and a reduction in the workability of the material. Post-process annealing is required to re-attain maximum corrosion resistant properties.
Cold Working
Most common cold work methods are successful with this alloy. It should be understood however that the material will be more difficult to work than other austenitic stainless steels due its high work hardening rate. The resulting hardening will, however, produce increases in strength and toughness which may be of value in the finished product.
Forging
This is a highly alloyed material and the recommended forging temperature range is 2370/1920ºF (1300/1050ºC), followed by a solution anneal at 2100ºF (1150ºC) minimum temperature.
آلية
Stainless steel grade 254 SMO™ is quite tough to machine due to the extremely high work hardening rate and lack of sulfur content; however using sharp tools,
overpowered machine tools, positive feeds, good amount of lubrication, and slow speeds tend to provide good machining results.
Weldability
The chemical analysis of 254 SMO grade is such that both ferrite and austenite are formed on cooling from welding, giving resistance to hot cracking. A postweld anneal is recommended, as is consultation with the product manufacturer regarding welding parameters.