254SMo Tubing 254SMo Pipe S31254 Tubing 6MO Seamless Tubing Pipe

ASME SA 213 ASTM A213 ASTM A269 S31254 254 SMo EN 10216-5 1.4547 Alloy 6Mo X1CrNiMoCuN20-18-7 Tubing is an superaustenitic stainless steel designed for maximum resistance to pitting and crevice corrosion. With high levels of chromium, molybdenum, and nitrogen, 254SMo is especially suited for high chloride environments such as brackish water seawater pulp mill bleach plants and other high chloride process streams. 254SMo Pipe offer chloride resistance superior to that of Alloy 904L, Alloy 20, Alloy 825 and Alloy G. Copper improved corrosion resistance in some of the acid . In addition, due to its high content of nickel,chromium and molybdenum, so that 254SMo S31254 Tubing has a good stress corrosion cracking performance.

254 SMo S31254 Tubing is compatible with the common austenitic stainless steels. In new construction, 254SMo has been found in many cases to be a technically adequate and much less costly substitute for nickel based alloys and titanium. 254SMo is substantially stronger than the common austenitic grade, also characterized by high ductility and impact strength. 254SMo is readily fabricated and welded.

254 SMo S31254 Tubing is face-centered cubic lattice structure. In order to obtain austenitic structure, 254 SMo S31254 Tubing general annealing in the 1150-1200°C. In some cases, the material may have traces of metal middle phase (χ phase and α-phase). However,their impact strength and corrosion resistance are not adversely affected in normal circumstances. When placed in the range of 600-1000°C, they may phase in the grain boundary precipitation.

• 254SMo Pipe Character
• 254SMo Pipe S31254 Chemical composition
• ASTM A213 ASME SA 213 S31254 254SMo Tubes Mechanical Properties
• ASTM A213 ASME SA 213 S31254 254SMo Tubing Physical Properties
• ASTM A213 ASME SA 213 S31254 254SMo Tubes Standard Specification
• S31254 254SMo Pipe Corrosion resistance
• 254 SMo S31254 Tubing S31254 Tubing Application
• ASTM A213 ASME SA 213 ASTM A269 S31254 254SMo Tubes Hot Working
• ASTM A213 ASME SA 213 ASTM A269 S31254 254SMo Tube Cold Working
• ASTM A213 ASME SA 213 ASTM A269 S31254 254SMo Pipe Welding
• 254SMo Pipe Marking and Packing
• 254SMo Pipe Exported Countries

254SMo Pipe Character

• A lot of a wide range use of experience has shown that even in higher temperature, 254 SMO S31254 Tubing in the sea water is also highly resistant to corrosion performance gap, only a few types of stainless steel with this performance.
• 254SMO S31254 Tubing such as bleach paper required for the production of acidic solution and the solution halide oxidative corrosion resistance and corrosion resistance can be compared to the most resilient in the base alloy of nickel and titanium alloys.
• 254SMO S31254 Tubing due to a high nitrogen content, so its mechanical strength than other types of austenitic stainless steel is higher. In addition, 254SMO S31254 Tubing also highly scalable and impact strength and good weldability.
• 254SMO S31254 Tubing with high molybdenum content can make it higher rate of oxidation in the annealing , which after the acid cleaning with rough surface than normal stainless steel is more common than the rough surface. However,has not adversely affected for the corrosion resistance of this steel .

254SMO Pipe S31254 Chemical composition

ASME SA213 S31254

ASTM A269 S31254

ASTM A213 ASME SA 213 S31254 254SMO Tubes Mechanical Properties

ASTM A213 ASME SA 213 ASTM A269 S31254 254SMO Tubing Physical properties:

254SMO Pipe Standard Specification

Seamless tube and pipe: ASTM A269, A213, A312, NFA 49-217, EN 10216-5
Welded tubeand pipe: ASTM A249, A269 , A312, A358, A409
Fittings: ASTM A182
Bar: ASTM A276, A479, EN 10088-3
Forged products: ASTM A473

ASTM A213/A213M-15 Standard Specification for Seamless Ferritic and Austenitic Alloy-Steel Boiler, Superheater, and Heat-Exchanger Tubes

 ASTM A269/A269M-15 Standard Specification for Seamless and Welded Austenitic Stainless Steel Tubing for General Service

EN 10216-5 Seamless steel tubes for pressure purposes

S31254 254SMO Pipe Corrosion resistance

254 SMo S31254 Tubing with very low carbon content, which means that the danger by the heating caused of carbide precipitation is very small. Even in the 600-1000°C after one hour sensitization still able to Strauss through the intergranular corrosion test (Strauss Test ASTMA262 order E).However, because of the high-alloy steel content. In the above-mentioned temperature range intermetallic phase with the possibility of metal in the grain boundary precipitation. These sediments do not make it occur intergranular corrosion in the corrosive media applications, then,welding can be carried out without intergranular corrosion.But in the heat of concentrated nitric acid, these sediments may be caused intergranular corrosion in heat-affected zone. If ordinary stainless steel in the solution that containing chloride, bromide or iodide,it will show pitting, crevice corrosion or stress corrosion cracking form by localized corrosion. However, in some cases,the existence of halide will speed up the uniform corrosion.

Particularly in the non-oxidizing acid. In pure sulfuric acid, 254 SMo S31254 Tubing with a much greater corrosion resistance than 316(common stainless steel),but with abated corrosion resistance compared to 904L (NO8904) stainless steel in high concentrations. In the sulfuric acid containing chloride ions , 254 SMo S31254 Tubing with the largest corrosion resistance ability.The 316 can not be used for stainless steel in hydrochloric acid since it may occur localized corrosion and uniform corrosion, but 254 SMo S31254 Tubing can be used in diluted hydrochloric acid in general temperatures,uder the border region do not need to worry about corrosion occurred. However, we must try to avoid the gap cracks. In the fluoride silicate (H2SiF4) and hydrofluoric acid (HF), the corrosion resistance of ordinary stainless steel is very limited, and 254 SMo S31254 Tubing can be used in a very wide temperature and concentration.

254 SMO S31254 Tubing S31254 Tubing Application

The most corrosion resistant stainless steel contains 6% to 7.3% Mo. Such as 254SMo alloy steel are used as power plant condensers, subsea pipelines, and key components of nuclear power plants, such as industrial water pipelines.

• 1. Petroleum, petrochemical equipment, petro-chemical equipment, such as the bellows. 
• 2. Pulp and paper bleaching equipment, such as pulp cooking, bleaching, washing filters used in the barrel and cylinder pressure rollers, and so on. 
• 3. Power plant flue gas desulphurization equipment, the use of the main parts: the absorption tower, flue and stopping plate, internal part,spray system. 
• 4. At sea or sea water processing system, such as power plants using sea water to cool the thin-walled Condenser, desalination of sea water processing equipment,can be applied even though the water may not flow in the device.
• 5. Desalination industries, such as salt or desalination equipment. 
• 6. Heat exchanger, in particular in the working environment of chloride ion.
• 7. Hydraulic Tubing and instrumention tubing
• 8. Tanks and pipelines for chemicals with high halide contents

ASTM A213 ASME SA 213 ASTM A269 S31254 Hot Working

Hot working should be carried out in the temperature range 1000-1200°C .  Higher temperatures will reduce the workability.  Fairly heavy scaling occurs at tempertaures exceeding 1150°C.

To ensure dissolution of possible precipitations of secondary phases from the hot forming, the subsequent heat treatment should take place at minimum 1150°C.  The material should then be cooled as quickly as possible.  A cooling rate that is too slow can result in reduced corrosion resistance.

ASTM A213 ASME SA 213 ASTM A269 S31254 Tubing Cold Working

254SMO pipe possesses very good cold formability.  Bending, pressing and other forming operations which are used in fabrication can be carried out without difficulty.  Practical experience obtained from the pressing of heat exchanger plates has been very favourable.  The steel work hardens rapidly.

ASTM A213 ASME SA 213 ASTM A269 S31254 Tubing Welding

254SMO alloy possesses good weldability.  When delivered, stainless steel sheets and plates have a homogeneous composition.  Remelting of the parent metal, such as during welding without filler metal, may cause microscale variations in composition for elements such as chromium, nickel and particularly molybdenum.  This phenomenon occurs in all highly alloyed stainless steels.  These variations may reduce the pitting resistance of the weld.   GTA and plasma arc welding without filler metal should therefore be avoided.

The material may not be subjected to abrasive contact with copper/brass items.  Penetration of copper/brass into the grain boundaries can give rise to crack formation.

Avesta P12 or P16 welding consumables should be used for all welding methods.

Ignite the electrode in the joint since ignition burns beside the weld can give rise to corrosion attacks.

Heat treatment is normally not necessary after welding.  However, welding without filler metal should be followed by solution annealing at 1150-1200°C and subsequent rapid cooling in order to achieve the best possible corrosion resistance.

To ensure optimum corrosion resistance the welds should be cleaned, preferably by pickling.

254SMO Pipe Marking and Packing

254SMO Pipes Export Countries