NorsokM001MaterialSelection

Package: neqsim.process.corrosion

Standards: NORSOK M-001, NACE MR0175 / ISO 15156

Material selection helper that recommends material grades for pipelines and process piping based on the corrosion environment. Integrates with NorsokM506CorrosionRate for CO2 corrosion rate input.

Evaluation Steps

The evaluate() method runs:

  1. Sour service classification — per NACE MR0175 / ISO 15156, based on H2S partial pressure
  2. Service category — sweet / sour / chloride / dry, considering free water
  3. Chloride SCC risk — pitting and stress corrosion cracking risk for stainless steels
  4. Material selection — recommended grade and alternatives based on all inputs
  5. Corrosion allowance — per NORSOK M-001 guidelines

Service Categories

Category Conditions
Dry service (no free water) No free water present
Non-corrosive service No CO2 or H2S with free water
Sweet service (CO2 only) CO2 present, H2S < 0.003 bar
Sweet + chloride service CO2 + chlorides, H2S < 0.003 bar
Sour service H2S >= 0.003 bar
Sour + chloride service H2S >= 0.003 bar + chlorides

Sour Classification (NACE MR0175)

Classification H2S Partial Pressure
Non-sour < 0.003 bar (0.3 kPa)
Mild sour (SSC Region 0) 0.003 – 0.01 bar
Moderate sour (SSC Region 1) 0.01 – 0.1 bar
Severe sour (SSC Region 2/3) > 0.1 bar

Material Selection Logic

Sweet Service (CO2 Only)

CO2 Rate (mm/yr) Low Chloride High Chloride (> 1000 mg/L)
< 0.1 Carbon steel (CS) CS
0.1 – 0.3 CS with increased CA CS with CA
0.3 – 1.0 13Cr martensitic SS 22Cr Duplex SS
> 1.0 22Cr Duplex SS 25Cr Super Duplex SS

Sour Service

Severity Low Chloride High Chloride
Mild/moderate, low rate CS (HIC/SSC tested per ISO 15156-2) 22Cr Duplex SS
Mild/moderate, high rate Super 13Cr (sour qualified) 22Cr Duplex SS
Severe 22Cr Duplex SS 25Cr Super Duplex / Alloy C-276

Chloride SCC Risk

Risk Level Conditions
Low Cl < 50 mg/L or T < 60 °C
Medium 50–1000 mg/L Cl at 60–100 °C
High > 1000 mg/L Cl at T > 80 °C
Very High > 50,000 mg/L at elevated T

Corrosion Allowance Rules

Material CA Rule
Carbon steel max(1.0 mm, rate * design_life), capped at 6.0 mm
Carbon steel (sour) Additional 1.0 mm for localized attack
CRA (13Cr, duplex, etc.) 0 mm — inherently resistant

CA > 6.0 mm triggers a note recommending CRA for lifecycle cost benefit.

Constructor

NorsokM001MaterialSelection selector = new NorsokM001MaterialSelection();

Input Setters

Method Default Description
setCO2CorrosionRateMmyr(double) 0.0 CO2 corrosion rate from M-506 or measured (mm/yr)
setH2SPartialPressureBar(double) 0.0 H2S partial pressure (bar)
setDesignTemperatureC(double) 60.0 Design temperature (°C)
setMaxDesignTemperatureC(double) 100.0 Max design temperature (°C)
setChlorideConcentrationMgL(double) 0.0 Chloride concentration (mg/L)
setDesignLifeYears(double) 25.0 Design life (years)
setAqueousPH(double) 4.5 pH of aqueous phase
setCO2PartialPressureBar(double) 0.0 CO2 partial pressure (bar)
setFreeWaterPresent(boolean) true Free water presence

Output Getters

Call evaluate() before accessing results.

Method Type Description
getServiceCategory() String Service classification
getRecommendedMaterial() String Recommended material grade with UNS number
getAlternativeMaterials() List<String> Alternative material options
getRecommendedCorrosionAllowanceMm() double Corrosion allowance (mm)
getMaterialMaxTemperatureC() double Max temperature for recommended material (°C)
getSourClassification() String NACE MR0175 sour classification
getChlorideSCCRisk() String SCC risk level
getNotes() List<String> Warnings and notes

JSON / Map Output

String json = selector.toJson();
Map<String, Object> map = selector.toMap();

Java Example

import neqsim.process.corrosion.NorsokM506CorrosionRate;
import neqsim.process.corrosion.NorsokM001MaterialSelection;

// Step 1: Calculate corrosion rate
NorsokM506CorrosionRate model = new NorsokM506CorrosionRate();
model.setTemperatureCelsius(80.0);
model.setTotalPressureBara(50.0);
model.setCO2MoleFraction(0.03);
model.setH2SMoleFraction(0.001);
model.setFlowVelocityMs(5.0);
model.setPipeDiameterM(0.254);
model.calculate();

// Step 2: Select material
NorsokM001MaterialSelection selector = new NorsokM001MaterialSelection();
selector.setCO2CorrosionRateMmyr(model.getCorrectedCorrosionRate());
selector.setH2SPartialPressureBar(model.getH2SPartialPressureBar());
selector.setCO2PartialPressureBar(model.getCO2PartialPressureBar());
selector.setDesignTemperatureC(80.0);
selector.setMaxDesignTemperatureC(80.0);
selector.setChlorideConcentrationMgL(5000);
selector.setDesignLifeYears(25);
selector.evaluate();

System.out.println("Material: " + selector.getRecommendedMaterial());
System.out.println("Service: " + selector.getServiceCategory());
System.out.println("Sour: " + selector.getSourClassification());
System.out.println("SCC risk: " + selector.getChlorideSCCRisk());
System.out.println("CA: " + selector.getRecommendedCorrosionAllowanceMm() + " mm");

for (String note : selector.getNotes()) {
    System.out.println("  - " + note);
}

Python Example

from neqsim import jneqsim

NorsokM506 = jneqsim.process.corrosion.NorsokM506CorrosionRate
NorsokM001 = jneqsim.process.corrosion.NorsokM001MaterialSelection

# Calculate corrosion rate
model = NorsokM506()
model.setTemperatureCelsius(80.0)
model.setTotalPressureBara(50.0)
model.setCO2MoleFraction(0.03)
model.setH2SMoleFraction(0.001)
model.setFlowVelocityMs(5.0)
model.setPipeDiameterM(0.254)
model.calculate()

# Select material
selector = NorsokM001()
selector.setCO2CorrosionRateMmyr(model.getCorrectedCorrosionRate())
selector.setH2SPartialPressureBar(model.getH2SPartialPressureBar())
selector.setDesignTemperatureC(80.0)
selector.setChlorideConcentrationMgL(5000)
selector.setDesignLifeYears(25)
selector.evaluate()

print(f"Material: {selector.getRecommendedMaterial()}")
print(f"Service: {selector.getServiceCategory()}")
print(f"CA: {selector.getRecommendedCorrosionAllowanceMm():.1f} mm")