S20910 / Nitronic 50 Pipe And Bar Special Alloys For Clean Energy And Oceaneering

Alloy 50 (S20910, Nitronic 50) pipe, strip, round and hexagonal bar, forging, fastener, wire for oceaneering

1 PRODUCT

Alloy 50 pipe, strip, round and hexagonal bar, forging, fastener, wire for oceaneering and marine application.

Alloy 50 is available in product forms as pipe, tube, sheet, strip, plate, round and hexagonal bar, forging, forging stock, wire, and fastener (bolts, nuts and studs etc).

2 EQUIVALENT DESIGNATION

Nitronic® 50, Alloy XM-19 / XM-19HS(ASTM), UNS S20910, W.Nr. 1.3964, X2CrNiMnMoNNb21.16.5.3, Aquamet 22, B8R, B8RA, AWS 165, Marinox 22, CarTech® 22Cr-13Ni-5Mn, Fermonic® 50

3 APPLICATION

Nitronic 50 stainless steel is useful in a myriad of industries, including marine, food processing, textiles, pulp and paper, nuclear fuel recycling, fertilizer, chemical, petrochemical, and petroleum.

The combination of high strength and superior corrosion resistance makes this alloy suitable for making components such as heat exchanger components, boat and pump shafting, marine hardware, screens and wire cloth, chains, cables, springs and fasteners, taper pins, valves, piping and fittings, pumps, pressure vessel, tanks, photographic equipment.

Useful in downhole rigging due to better corrosion and double the yield strength in annealed condition.

4 OVERVIEW

Nitronic 50 is a nitrogen-strengthened austenitic stainless steel with an excellent combination of strength, ductility, toughness, corrosion resistance and fabricability. Nitronic 50 provides corrosion resistance greater than other typical austenitic grades such as SS316/316L and SS317/317L. It is also capable of nearly double the yield strength of similar austenitic grades. Nitronic 50 stainless steel offers yield strength three times that of 316.

Features

Very good mechanical properties at both elevated (up to 1200°F / 649°C) and sub-zero temperatures

Excellent corrosion resistance at both high and minus zero temperatures, even in the most agressive situations.

Low magnetic permeability even after severe cold working or exposure to sub-zero temperatures.

Amagnetic even after severe forming operations.

5 CHEMICAL COMPOSITION (wt%):

6 PHYSICAL PROPERTY

Density: 7.88 g/cm³ (0.285lb/in³)

Melting range: 1415-1450°C (2579-2624°F)

Thermal conductivity 14 (W.m.K.)

Specific heat 476 Joule (kg.K) ((0.11 Btu/lb/Deg F - [32-212 Deg F])

Poissons Ratio: 0.298

Electrical resistance 0.82 Ω mm²/m

Modulus of elasticity 199 x 10³ N/mm²(28500 ksi)

Modulus of rigidity: 78.9 kN/mm² (11444 ksi)

Magnetic properties Non magnetic

7 MECHANICAL PROPERTIES

Yield strength 0.2% (N/mm2) Min. 380

Tensile strength (N/mm2) Min. 690

Reduction of area Min. 55

Elongation % Min. 35

Hardness (HB) Max. 293

8 CORROSION RESISTANCE

Nitronic 50 Stainless Steel provides outstanding corrosion resistance - superior to Types 316, 316L, 317 and 317L in many reducing and oxidizing acids, chlorides, and pitting environments. In particular, the alloy provides an excellent level of resistance to pitting and crevice corrosion in sea water, tests have shown it to be completely unaffected after 9 months in quiet sea water. Resistance to intergranular attack in boiling 65% nitric acid and in ferric sulfate-sulfuric acid (ASTM A262, practices B and C) is excellent for both the annealed and sensitized conditions. Like other austenitic stainless steels, Carpenter 22Cr-13Ni-5Mn, under certain conditions, may stress-corrosion crack in hot chloride environments. The alloy also demonstrates good resistance to sulfide stress cracking at ambient temperatures. It is included in NACE MR-01-75, "Sulfide Stress Corrosion Cracking Resistant Metallic Materials for Oil Field Equipment" at a maximum hardness of Rockwell C 35.

For many applications the 1950°F (1066°C) annealed condition provides adequate corrosion resistance and a higher strength level. In very corrosive media or where material is to be used in the as-welded condition, the 2050°F (1121°C) annealed condition should be specified. High-Strength (HS) NITRONIC 50 bars are useful for applications such as shafting and bolting, but do not quite exhibit the corrosion resistance of the annealed conditions in all environments.

9 WORKING INSTRUCTION

The alloy may be machined, welded and cold worked using the same equipment used for normal austenitic stainless steels. The alloy displays a combination of strength, ductility, toughness, corrosion resistance and fabricability.

Hot working

The alloy can be forged, hot rolled, hot headed and upset. An initial forging temperature of 2100/2200ºF (1150/1205ºC) is normally used. Preheating to an intermediate temperature is not required. Forgings can be rapidly cooled without danger of cracking. For best corrosion resistance, anneal after forging.

Heat to 2000°F, soak to equalize, then heat to 2150 and equalize prior to hot working.

Forming

All common forming techniques can be used with this alloy. Springback will be greater than with standard austenitics and should be taken into consideration when choosing the appropriate forming forces. Process annealing is recommended to remove stresses resulting from this alloys' high work hardening rate.

Cold working

The alloy can be cold formed by drawing, bending, upsetting and stamping. Because of its higher strength and work-hardening rate, the force required is somewhat greater than for Types 302, 304 and 316. The high work-hardening rate can be advantageous when cold working to increase strength; i.e., high strengths with good ductility can be achieved with less reduction.

Annealing

Annealing is carried out at 1950-2050ºF (1066-1121ºC), hold 20 minutes, followed by rapid cooling. Thin sections are usually cooled in air and heavy sections in water, depending upon section size.

For most applications, the 1950 F (1066 C) condition should be selected, as it provides a higher level of mechanical properties along with excellent corrosion resistance. When as-welded material is to be used in strongly corrosive media, the 2050 F (1121 C) condition should be specified in order to minimize the possibility of intergranular attack.

Hardening

Hardening this alloy requires cold working. It will not harden with exposure to thermal treatment.

Machinability

This alloy has a machinability rating about 30% of AISI 1212. Slow to moderate speeds, moderate feeds and rigid tools should be considered; tools must be kept sharp. Chips tend to be tough and stringy. Chip curlers or breakers are helpful. Use a sulfurized cutting fluid, preferably of the chlorinated type.
Slow speeds, positive feeds and abundant resulphurized lubricant are essential to success in machining this alloy. Speeds and feeds similar to those employed with 316 or 317 stainless are appropriate here. All common machining practices can be used on this material. Chips will be tough and stringy and it is recommended that curlers or breakers are used.

10 STANDARD SPECIFICATION

This alloy is included in NACE MR-01-75, "Sulfide Stress Corrosion Cracking Resistant Metallic Materials for Oil Field Equipment" at a maximum hardness of Rockwell C 35.

ASTM A182 (XM-19)

ASTM A193 (B8R, B8RA)

ASTM A194 (B8R, B8RA)

ASTM A213

ASTM A240(XM-19)

ASTM A249 (XM-19)

ASTM A269 (XM-19)

ASTM A276

ASTM A312 (XM-19)

ASTM A336 (XM-19)

ASTM A403 (XM-19)

ASTM A412 (XM-19)

ASTM A479 (XM19)

ASTM A580 (XM-19)

ASTM A813 (TP XM-19)

ASTM F1314 (UNS S20910)

AMS 5861

AMS 5764

A5.9 ER209

NACE MR0175 (ISO 15156-3)

11 COMPETITIVE ADVANTAGE

(1) More than 50 years experience of research and develop in high temperature alloy, corrosion resistance alloy, precision alloy, refractory alloy, rare metal and precious metal material and products.
(2) 6 state key laboratories and calibration center.
(3) Patented technologies.

(4) Ultra-purity smelting process: VIM + IG-ESR + VAR

(5) Excellent high performance.

12 BUSINESS TERM