Sanicro 41 (Billets)

Chemical composition (nominal) %

Forms of supply

Sizes and tolerances

Round-cornered square, as well as round billets, are produced in a wide range of sizes according to the following tables. Larger sizes offered on request.

Surface conditions

Square billets

Unground, spot ground or fully ground condition.

Round billets

Peel turned or black condition.

Sizes and tolerances apply to the rolled/forged condition.

Other products

• Welding wire
• Covered electrodes
• Seamless tube and pipe
• Hollow bars

Mechanical properties

Sanicro 41 conforms to the required mechanical properties according to specification ASTM B564. Testing is performed on separately solution annealed and quenched test piece.

At 20 ^oC

At 68 ^oF

1) Corresponds to 0.2 % offset yield strength

At high temperatures

Fig. 1 shows indicative values for tensile strength properties of Sanicro 41 at high temperatures.

Figure 1. Minimum high temperature tensile strength properties for Sanicro 41 are based on datasheets seamless tube and pipe. Since the tubes have thin walls the values should only be used as indicative values for forgings. (Proof strength corresponds to 0.2% offset yield strength.)

Physical properties

1) typical value

1) typical value

1) typical values (x10^-6)

Corrosion resistance

General corrosion

Sanicro 41 possesses excellent resistance to corrosion. The material is clearly superior to standard molybdenum-alloyed steels such as AISI 316L, particularly when exposed to non-oxidizing media, such as sulphuric or phosphoric acid. The resistance to highly oxidizing agents, such as nitric acid, is also satisfactory.

Pitting and crevice corrosion

The resistance of Sanicro 41 to pitting and crevice corrosion is superior to that of AISI 316 - a result of the higher chromium and molybdenum contents in the material.

Stress corrosion cracking

The high nickel content of the material promotes excellent resistance to stress corrosion cracking induced by both chlorides and alkalis. Sanicro 41 has shown excellent resistant to stress corrosion cracking in sour environments.

Intergranular corrosion

Since the material is titanium-stabilized, the risk of intergranular corrosion is minimized.

For further information on corrosion resistance of Sanicro 41, please see the datasheet - Seamless tube and pipe Sanicro 41. The data should be considered in the knowledge that it may not be applicable for thick sections, such as forgings.

Hot working

The hot forming range for Sanicro 41 is 900-1175°C (1740-2150°F), followed by quenching in water. Subsequent heat treatment should be carried out in accordance with the recommendations given for heat treatment.

Heat treatment

Billets are delivered in hot worked condition. The following heat treatment is recommended for finished products.

Solution annealing

930-980°C (1700-1800°F) followed by quenching in water.

Welding

The weldability of Sanicro 41 is good. Suitable methods of fusion welding are manual metal-arc (MMA), tungsten inert gas (TIG) and metal inert gas welding (MIG). Preheating and post-weld heat treatment are normally not necessary.

The standard of cleanliness required when welding fully austenitic stainless steels is particularly strict. Joint surfaces and filler metals must be free from grease, paint and other contaminants. The weld zone should be cleaned, as required, using a suitable solvent, such as acetone or alcohol.

Sanicro 41, like other austenitic materials, has a high coefficient of thermal expansion. Welding should, therefore, be carried out with a low heat input, using well prepared welding procedures to control distortion of the welded construction.

As fully austenitic materials are rather sensitive to hot cracking, welding should be carried out with the lowest practical heat input, <1.0kJ/mm and an interpass temperature of < 100°C (210 ^oF).

The recommended filler metal for TIG and MIG welding is Sandvik 27.31.4.LCu. For both TIG and MIG/MAG welding, pure argon should be used as a shielding gas and for MIG/MAG welding a pulsed current is suggested. For manual metal-arc welding (MMA), Sandvik 27.31.4.LCuR is the recommended choice.

Machining

Machining Sanicro 41, as with other stainless steels, requires an adjustment to tooling data and machining method, in order to achieve satisfactory results. Compared to Sanmac 316/316L, the cutting speed must be reduced by approximately 55-60%, when turning Sanicro 41 with coated, cemented carbide tools. Much the same applies to other operations. Feeds should be reduced by approximately 10-15% and with care.

Detailed recommendations for the choice of tools and cutting data are provided in the data sheet for Sanmac 316/316L.

Applications

Sanicro 41 has good resistance to general and localized corrosion under diverse conditions. Applications can be found in chemical processing, oil and gas production, acid production, pickling operations and corrosive environments containing sulphuric acid, phosporic acid, sulphur containing gases, oil wells and sea water.