Sandvik Bioline 3R65 (Tube and pipe, seamless)

Applications

Thick wall tubes applications:

Sandvik Bioline 3R65 is used in a wide variety of industrial applications. For medical industry, Sandvik Bioline 3R65 is used for medical tools.

Thin wall tubes applications:

Biopsy punches, mammography machine, brooches, suspension for oxygen tank for hospital mobile beds, surgical and dental tools.

Bending

Annealing after cold bending is not normally necessary, but this point must be decided with regard to the degree of bending and the operating conditions. Heat treatment, if any, should take the form of stress-relieving or solution annealing, see under "Heat treatment".

Hot bending is carried out at 1100-850°C (2010-1560°F) and should be followed by solution annealing.

Chemical composition (nominal) %

Corrosion resistance

General corrosion

Sandvik Bioline 3R65 has good resistance to:

• Organic acids at high concentrations and temperatures, with the exception of formic acid and acids with corrosive contaminants
• Inorganic acids, e.g. phosphoric acid, at moderate concentrations and temperatures, and sulphuric acid below 20% at moderate temperatures. The steel can also be used in sulphuric acid of concentrations above 90% at low temperature
• Salt solutions, e.g. sulphates, sulphides and sulphites

Intergranular corrosion

Sandvik Bioline 3R65 has a low carbon content and therefore better resistance to intergranular corrosion than other steels of type AISI 316.

Pitting and crevice corrosion

Resistance of these types of corrosion improves with molybdenum content. Sandvik Bioline 3R65 has substantially higher resistance to attack than steels of type AISI 304.

Stress corrosion cracking

Austenitic steels are susceptible to stress corrosion cracking. Stress corrosion cracking may occur if the steel is simultaneously exposed to the following:

• Tensile stresses
• Certain solutions, particularly those containing chlorides
• Temperatures above 60^oC (140^oF)

Such service conditions should therefore be avoided. Conditions when plants are shut down must also be considered, as the condensates which are then formed can develop a chloride content that leads to both stress corrosion cracking and pitting.

In applications demanding high resistance to stress corrosion cracking, austenitic-ferritic steels, e.g. Sandvik SAF 2304 or SAF 2205 are recommended.

Gas corrosion

Sandvik Bioline 3R65 can be used in

• Air up to 850^oC (1560^oC)
• Steam up to 750^oC (1380^oF)

In flue gases containing sulphur, the corrosion resistance is reduced. In such environments Sandvik Bioline 3R65 can be used at temperatures up to 600-750^OC (1110-1380^OF) depending on service conditions. Factors to consider are whether the atmosphere is oxidising or reducing, i.e. the oxygen content, and whether impurities such as sodium and vanadium are present.

Forms of supply

Seamless tube and pipe- Finishes and dimensions

Seamless tube and pipe in Sandvik Bioline 3R65 are supplied in dimensions up to 260 mm outside diameter in the solution annealed and white-pickled condition or in the bright-annealed condition.

Dimension range for tubes, thin wall

OD : 0.5 - 50.80 mm
Wall thickness : 0.1 - 3 mm
Fine tube tolerances :

• Wall thickness tolerance : +/- 10%
• OD tolerance : +/- 0.75% with a minimum of +/-0.02 mm
• Roughness
  for OD> 5mm Ra (outside) < 0.4 (by polishing)
  for ID>3.2mm Ra (inside)< 0.4 - this possibility depends on wall thickness/diameter ratio
  Specific roughness can be done on request
• Internal cleaning can not be done for inside diameter below 4 mm

All products supplied either in the annealed and cold worked condition to provide mechanical properties as required

Heat treatment

The tubes are delivered in heat treated condition. If additional heat treatment is needed after further processing the following is recommended.

Stress relieving

850-950°C (1560-1740°F), 10-15 minutes, cooling in air.

Solution annealing

1000-1100°C (1830-2010°F), 5-20 minutes, rapid cooling in air or water.

Machining

Sandvik Bioline 3R65 has good machining properties. However the machining of Sandvik Bioline 3R65, as with other stainless steels, requires an adjustment of tooling data and machining method, in order to achieve satisfactory results. Compared to Sanmac 316/316L, the cutting speed must be reduced by approximately 30-40 % when turning Sandvik Bioline 3R65 with coated, cemented carbide tools. Much the same applies to other operations.

Feeds should only be reduced slightly and with care.

Detailed recommendations for the choice of tools and cutting data are provided in the brochure S-02909-ENG. Data should be selected as for steel grade Sanmac 316/316L, while taking into account the provisions above.

Mechanical properties

Thin wall tubes

Sandvik Bioline 3R12 can be supplied in bright annealed or cold worked condition with R_m 860-1100 MPa

Thick wall tubes

For tube and pipe with wall thicknesses greater than 10 mm (0.4 in.) the proof strength may fall short of the stated values by about 10 MPa (1.4 ksi).

At 20°C (68°F)

Mechanical properties can be set according to your demands.

1 MPa = 1 N/mm²
a) R_p0.2 and R_p1.0 correspond to 0.2% offset and 1.0% offset yield strength, respectively.
b) Based on L₀ = 5.65√S₀ where L₀ is the original gauge length and S₀ the original cross-section area.

Impact strength

Due to its austenitic microstructure, Sandvik Bioline 3R65 has very good impact strength both at room temperature and at cryogenic temperatures.

Tests have demonstrated that the steel fulfils the requirements (60 J (44 ft-lb) at -196 ^oC (-320 ^oF)) according to the European standards EN 13445-2 (UFPV-2) and EN 10216-5.

At high temperatures

Physical properties

Density: 8.0 g/cm³ , 0.29 lb/in³

1) Mean values in temperature ranges (x10^-6)

Welding

The weldablity of Sandvik Bioline 3R65 is good. Suitable welding methods are manual metal-arc welding with covered electrodes and gas-shielded arc welding with the TIG and MIG methods as first choice. Preheating and post-weld heat treatment are not normally necessary.

Since the material has low thermal conductivity and high thermal expansion, welding must be carried out with a low heat input and with welding plans well thought out in advance so that the deformation of the welded joint can be kept under control.

As filler material for gas-shielded arc welding we recommend wire electrodes and rods Sandvik 19.12.3.L, 19.12.3.LSi or, when a ferritic-free weld metal is required, 25.22.2.LMn. In manual metal-arc welding covered electrodes Sandvik 19.12.3.LR or 19.12.3.LRHD are recommended and as a ferrite free alternative 25.22.2.LMnB.