Material Data Sheet

Please select a material application among SM series and proprietary grades.

Nickel Alloy - SM2535-125

Coupling: Cu Plated, Green, Orange, Orange
Pipe body: Green, Orange, Orange
General description

SM2535 is an Austenitic Fe (Iron) base material required for critical well conditions combining high concentrations of CO2, H2S and Chlorides. Launched in the mid-80’s as an innovative development, SM2535 has become the reference product for Tubing & Liner applications in severe environments. It benefits from Nippon Steel’s unrivaled know-how in manufacturing CRA (Corrosion Resistance Alloys) materials and best-in-class quality control.

SM2535-125 is manufactured based on API 5CT / ISO 11960 and API 5CRA / ISO 13680.

Diameters: 2 3/8” to 7 5/8” (larger sizes can be available upon request)

Weights: as per API 5CT/ISO 13680. Please note that while the API 5CT/ISO 11960 linear weight will define the pipe wall thickness the actual linear weight of the material will be slighter greater due to the heavier density of the elements it contains versus carbon steel.

Special application: Please contact Nippon Steel engineer, should you require specific size, weight, drift, or any other characterization.

Reference document
Applicable environment

Corrosive environments featuring the combined presence of CO2 + H2S + Chloride, in temperatures up to 149 °C, in absence of elemental Sulfur

Its primary function is Tubing and Liner, sections permanently exposed to production fluids

Final material application will depend upon CO2, H2S, Temperature, pH and expected Chlorides content. For a more detailed assessment please contact Nippon Steel engineers.

Manufacturing
PROCESS DESCRIPTION
Steel making Steel shall be made by electric furnace process followed by Vacuum Oxygen Decarburization (VOD) process &/or Argon Oxygen Decarburization (AOD) Process
Pipe making Manufactured through Cold working the hot formed tubular product and shall be furnished in a cold worked conditions
Heat treatment Solution Annealing Process before final cold drawing
Chemical composition

(mass %)

C Si Mn Cu Ni Cr Mo
≤ 0.03 ≤ 0.50 ≤ 1.00 ≤ 1.50 29.5 ~ 36.5 24.0 ~ 27.0 2.5 ~ 4.0

UNS Number: N08535

Specified mechanical properties
YIELD STRENGTH
KSI		 TENSILE STRENGTH
KSI		 ELONGATION
%		 HARDNESS
HRC		 TECHNICAL NOTE
Min Max Min Min  Max  
125 145 130 10 34.0 -
Physical and thermal properties
  UNIT 25°C 100°C 150°C 200°C 250°C
Density Kg/m3 8020 7990 7980 7960 7940
Young's modulus GPa 190 187 184 182 180
Poisson's Ratio - 0.29 0.29 0.29 0.29 0.29
Tensile strength de-rating % 100.0 93.5 89.9 87.8 85.1
Yield strength de-rating % 100.0 93.4 90.7 88.3 86.1
Thermal Diffusivity x10-6 m2/s 2.97 3.36 3.56 3.69 3.90
Heat Capacity x106 J/m3 deg.C 2.94 3.05 3.09 3.14 3.19
Thermal Conductivity W/m deg.C 8.7 10.3 11.0 11.6 12.4
Specific Heat J/Kg deg.C 366 382 387 395 402
Thermal expansion x10-6 / deg.C - 14.9 15.0 15.2 15.4

* Data will be shortly available.

SM2535 Temperature

 

Technical information

In wet combined CO2 & H2S environments, usage of SM2535 is recommendable starting from H2S partial pressure exceeding 0.1 bar:

  • for lower H2S partial pressure ranging between 0.1 to 1.0 bar, these  materials should be considered depending upon the combination of critical variables such as pH, Chloride content, S0 and temperature.
  • for H2S partial pressures exceeding 1.0 bar the only metallurgical solution to counter corrosion is to consider Austenitic Fe base or Nickel base materials.

Since H2S is a potent pitting agent, a passivation film  composed of Ni-S, Cr-O & Mo-S is required to maintain stability and protect the bulk material from corrosion attack up to a defined temperature threshold in wet combined CO2 & H2S environment. This is achieved through alloying of Cr-Ni & Mo.

SM2535 is a nominal 3% Molybdenum material recognized by ISO-13680 as Group 3 Category 25-32-3. This material is referenced as 4c material in NACE MR0175 /ISO 15156-3 (please refer to Fig. 1)

NACE MR0175

Fig 1: NACE MR0175 / ISO 15156-3 2003 Table A12

For this type of material, NACE MR0175 /ISO 15156-3 indicate the following application limits as general guidelines :

Material 4c application boundaries

Fig 2: Material 4c application boundaries per NACE MR0175 / ISO 15156-3 2003 (Ref. Table A-14)

According to NACE MR0175 / ISO 15156-3 2003, final material selection for the intended service will be equipment user’s responsibility and detailed information exchange with manufacturer is highly recommendable.

Nippon Steel, in absence of elemental sulfur, recommends usage of SM2535 materials for temperature up to 149°C (300°F) higher than 132°C (270°F) limit specified by ISO 15156-3.

This difference is based on Nippon Steel’s unrivaled know-how in manufacturing austenitic stainless steel since the mid 80’s and best-in-class quality control.

For fit for purpose conditions (** in Fig 2), Nippon Steel proposes verification test under the actual field condition.

Fig 3 below represents Nippon Steel SCC limits on various Austenitic materials.

Relation between testing temperature

Fig. 3: Relation between testing temperature and Mo content of Nickel Alloy in
H2S- Cl- environment in SSRT (25% NaCl+ CH3COOH, 0.7 MPa (100 psi) H2S)

For additional information about material performances please contact Nippon Steel engineers.

Case history from the field

A selection of critical applications of SM2535 is shown below. These Field records include SM2535 material used as Tubing and Liner.

SM2535 applications

 

Storage and handling procedures

While state-of-the-art HSE rules are applied throughout Nippon Steel manufacturing process, proprietary and specific HSE regulations shall be applied along the life cycle of the pipe until it reaches its final position in the well, according to each operator’s rules. This particularly applies to all phases of handling and transportation, assembly on the rig floor, and rig return if applicable. OCTG are heavy and by nature unstable. Special care shall be paid to potential risks of injury whenever handling OCTGs. Walking on pipes shall be avoided at all times. Usage of Personal Protection Equipments (PPE) is mandatory. Equipment and procedures will be established to capture the possible wastes generated during maintenance (cleaning, coating, doping) and disposed according to local regulations. This applies in particular to storage dope, running dope, or cleaning water wastes.

Best practices for transportation, handling and storage of OCTG in general are covered by ISO 10405 / API RP5C1. VAM Book is also a good source of handling practices for VAM connections. In addition to these general rules, specific care is recommended pertaining to SM-2535, because improper handling could affect the material performances and by extension the corrosion resistance :

  • Prevention of Spot Hardening
  • Prevention of Iron contamination
  • Adapted running equipments and practices
  • Prevention of corrosion on rig returns, particularly in presence of completion fluids

For more specific information please refer to Nippon Steel Storage and handling procedure for CRA materials or contact Nippon Steel engineers.