NACE MR0175/ISO 15156-01 and MR 0103
Materials Requirements for Sour Services
• The consequences of sudden failures of metallic oil and gas field
components ,associated with their exposure to H2S-containing
production fluids lead to the preparation of the first edition of NACE
MR0175 which was published in 1975 by the National Association
of Corrosion Engineers.
• In 2003 ,NACE MR0175 merged with ISO 15156 and it supersedes
all previous version of MR0175.
CNQ
PREMIUM VALUE | DEFINED GROWTH | INDEPENDENT
Slide 2
NACE MR0175/ISO 15156-01 and MR 0103
Materials Requirements for Sour Services
• The NACE Standard MR-0103 establishes material requirement for
resistance to sulfide stress cracking (SSC) in sour refinery process
environments.
• The NACE Standards MR-0175/ISO-15156 establishes materials
for use in H2S-containing environments in oil and gas production.
• High concentration of CO2 and Chloride are present in this
environments as well.
CNQ
PREMIUM VALUE | DEFINED GROWTH | INDEPENDENT
Slide 3
NACE MR0175/ISO 15156-01 and MR 0103
Materials Requirements for Sour Services
• NACE MR-0175/ISO-15156 Standard is comprised on the following
three parts:
Part 1: General Principles for Selection of Cracking-Resistant
Materials.
Part 2: Cracking Resistant Carbon and Low –Alloy Steels, and the
Use of Cast Irons
Part 3: Cracking-Resistance CRAs(Corrosion-Resistance Alloys)
and Others Alloys.
CNQ
PREMIUM VALUE | DEFINED GROWTH | INDEPENDENT
Slide 4
Part 1: General Principles for Selection of
Cracking-Resistant Materials.
Part 1 describes general principles and gives requirements and
recommendation for the selection of materials for service in
equipment used in oil and gas production in H2S –containing
environments ,where the failure could pose a risk to the health and
safety of the public and personnel.
CNQ
PREMIUM VALUE | DEFINED GROWTH | INDEPENDENT
Slide 5
Part 1: General Principles for Selection of
Cracking-Resistant Materials.
• Part 1 addresses seven mechanisms of cracking that can occur in
oil and gas production environments containing H2S:
1.
2.
3.
4.
5.
6.
7.
CNQ
Sulfide Stress Cracking (SSC)
Stress Corrosion Cracking (SCC)
Hydrogen-induced Cracking (HIC)
Stepwise Cracking (SWC)
Stress-Orientated Hydrogen Induced Cracking (SOHIC)
Soft Zone Cracking (SZC)
Galvanically Induced Hydrogen Stress Cracking (GIHSC)
PREMIUM VALUE | DEFINED GROWTH | INDEPENDENT
Slide 6
Part 1: General Principles for Selection of
Cracking-Resistant Materials.
• WARNING
• Metallic materials selected using NACE MR0175/ISO15156 are
resistant to cracking in defined H2S-containing environments in oil
and gas production ,but NOT NECESSARILY IMMUNE to cracking
under all service condition.
• It is the equipment user’s responsibility to select materials suitable
for the intended service!
• Therefore, before selecting or qualifying materials, the user of the
equipment shall defined ,evaluate and document the service
condition to which materials can be exposed .
CNQ
PREMIUM VALUE | DEFINED GROWTH | INDEPENDENT
Slide 7
Part 1: General Principles for Selection of
Cracking-Resistant Materials.
• Evaluation and Service Condition:
• Factors, others than material properties ,known to affect
susceptibility of materials to cracking in H2S service include:
H2S partial pressure
In situ pH
Presence of elemental sulfur or other oxidant
Temperature
Galvanic effect
Mechanical stress
Time to exposure to contact with a liquid water phase.
CNQ
PREMIUM VALUE | DEFINED GROWTH | INDEPENDENT
Slide 8
Part 2: Cracking Resistant Carbon and LowAlloy Steel, and the use of Cast Irons
• This part addresses the resistance of these steels to damage that
can be caused by:
1. Sulfide Stress Cracking (SSC)
2. Stress-Orientated Hydrogen Induced Cracking (SOHIC)
3. Soft Zone Cracking (SZC)
4. Hydrogen-induced Cracking (HIC)
5. Stepwise Cracking (SWC)
This part is concerned only with cracking. Localized corrosion is not
addressed.
CNQ
PREMIUM VALUE | DEFINED GROWTH | INDEPENDENT
Slide 9
Part 2: Cracking Resistant Carbon and LowAlloy Steel, and the use of Cast Irons
• The behavior of carbon and low-alloy steel in H2S environments are
affected by:
Chemical composition ,strength ,hardness , product form .
Grain size
H2S partial pressure
Acidity (pH) of the water phase
Exposure temperature
Exposure time
Tensile stress
Presence of elemental sulphur
CNQ
PREMIUM VALUE | DEFINED GROWTH | INDEPENDENT
Slide 10
Part 2: Cracking Resistant Carbon and LowAlloy Steel, and the use of Cast Irons
• There are three main ways to qualify and selecting carbon and lowalloy steels with resistance to SSC
1. Qualification by “pre-qualified” materials
2. Qualification by laboratory testing
3. Qualification by 2 years of documented field experience
Within the “pre-qualified” materials choice ,there are two options:
Option 1: For partial pressure H2S below 0.3KPa no special
precaution are required
For partial pressure H2S equal to or greater 0.3KPa the
material shall be heat-treated and maximum hardness 22HRC.
Option 2: Using diagrams based upon partial pressure of H2S and
the pH of the process.
CNQ
PREMIUM VALUE | DEFINED GROWTH | INDEPENDENT
Slide 11
Part 2: Cracking Resistant Carbon and LowAlloy Steel, and the use of Cast Irons
• Hardness Testing Requirements for Welds
• The qualification of welding procedures for sour services shall
include hardness testing using the Vickers HV10 or HV5 method in
accordance with ASME E92 or Rockwell 15 N scale in accordance
with ASME E18
• Figure 1 shown below the butt weld survey method for Vickers
hardness measurement.
• Hardness acceptance criteria for carbon steel and low-alloy steel
welds are specified in Part 2.
CNQ
PREMIUM VALUE | DEFINED GROWTH | INDEPENDENT
Slide 12
Survey method for Vickers hardness
measurement
• Hardness impressions within heat affected zones should be located
as close as possible to the fusion boundary .
CNQ
PREMIUM VALUE | DEFINED GROWTH | INDEPENDENT
Slide 13
Heat –Affected Zones
CNQ
PREMIUM VALUE | DEFINED GROWTH | INDEPENDENT
Slide 14
Part 3 Cracking-resistant CRAs (corrosionresistant alloys) and others alloys
• This part gives requirements and recommendation for the selection
and qualification of CRAs(corrosion-resistant alloys) and other
alloys for service in equipment used in H2S containing environment.
• Part 3 address the resistance of these materials to damages that
can be caused by:
Sulfide Stress Cracking(SSC)
Stress Corrosion Cracking(SCC)
Galvanically Induced Hydrogen Cracking
This part is concerned only with cracking. Localized corrosion is not
address.
CNQ
PREMIUM VALUE | DEFINED GROWTH | INDEPENDENT
Slide 15
Part 3 Cracking-resistant CRAs (corrosionresistant alloys) and others alloys
• Cracking-resistance CRAs and others alloys could be selected:
Using “pre-qualified “ material Annex A
Following qualification by successful laboratory testing in
accordance to Annex B
Based on satisfactory 2 years of documented field experience.
Hardness Testing Requirements for welds are the same as on Part 2
CNQ
PREMIUM VALUE | DEFINED GROWTH | INDEPENDENT
Slide 16
NACE MR 0103 Materials Resistant to Sulfide Stress
Cracking in Corrosive Petroleum Refining Environments
• Scope:
• This standard establishes material requirements for resistance to
Sulfide Stress Cracking (SSC) in sour petroleum refining and
related processing environment containing H2S either as a gas or
dissolved in liquid water with or without presence of hydrocarbon.
• Applicability:
• This standard applies to all components of equipment exposed to
sour refinery environments where failure by SSC would
compromise the integrity of the pressure system.
CNQ
PREMIUM VALUE | DEFINED GROWTH | INDEPENDENT
Slide 17
NACE MR 0103 Materials Resistant to Sulfide Stress
Cracking in Corrosive Petroleum Refining Environments
• SSC is defined as cracking of a metal under the combined action of
tensile stress and corrosion in the presence of water and H2S.
• SSC is a form of hydrogen stress cracking resulting from absorption
of atomic hydrogen that is produced by the sulfide corrosion
reaction. The atoms remain dissolved in the matrix and are highly
mobile.
• SSC is observed in the welds or heat affected zones where highstrength/low-ductility microstructure may be present and can be
identified by high hardness.
CNQ
PREMIUM VALUE | DEFINED GROWTH | INDEPENDENT
Slide 18
NACE MR 0103 Materials Resistant to Sulfide Stress
Cracking in Corrosive Petroleum Refining Environments
• Factors contributing to SSC:
Chemical composition
Strength (as indicated by hardness)
Heat treatment
Microstructure of the material
The hydrogen flux in the material
Temperature
Time
CNQ
PREMIUM VALUE | DEFINED GROWTH | INDEPENDENT
Slide 19
NACE MR 0103 Materials Resistant to Sulfide Stress
Cracking in Corrosive Petroleum Refining Environments
• Environmental condition known to cause SSC are those containing
an aqueous phase and:
>50 ppmw total sulfide content, OR
≥1 ppmw total sulfide content and PH<4, OR
≥ 1ppmw total sulfide contents and ≥ 20 ppmw free cyanide and
PH>7.6, OR
>0.3 kPa absolute partial pressure H2S in the gas phase
associated with the aqueous phase of a process.
CNQ
PREMIUM VALUE | DEFINED GROWTH | INDEPENDENT
Slide 20
CNRL Standard 00-STD-MW-0034
CNRL Standard 00-STD-MW-0034 identify three levels of “Wet H2S
Service :
Category 1-Mildly corrosive
H2S concentration is 50 to 2,000 ppmw
PH range is 4.5 to 7.
Category 2-Moderately corrosive
H2S concentration is 2,000 to 2,500 ppmw
PH range is 4.5 to 7.6
Category 3-Severaly corrosive
H2S concentration is greater than 2,500 ppmw
PH is below 4.5
CNQ
PREMIUM VALUE | DEFINED GROWTH | INDEPENDENT
Slide 21
NACE MR 0103 Materials Resistant to Sulfide Stress
Cracking in Corrosive Petroleum Refining Environments
Hardness is related to tensile strength, a primary factor in SSC
susceptibility .As such, a maximum allowable hardness is specified as a
primary requirement for materials.
CNQ
PREMIUM VALUE | DEFINED GROWTH | INDEPENDENT
Slide 22
NACE MR 0103 Materials Resistant to Sulfide Stress
Cracking in Corrosive Petroleum Refining Environments
• Alloy steel included under the ASME Sec. IX P-No shall not exceed
g maximum hardness level:
Alloy Steel
Maximum Hardness
P-No. 3
225 HBW
P-No. 4
225 HBW
P-No. 5A
235 HBW
P-No. 5B
235 HBW
P-No. 5C
235 HBW
P-No. 6
235 HBW
P-No. 7
235 HBW
P-No. 10A
225 HBW
P-No. 10B
225 HBW
P-No. 10C
225 HBW
P-No. 10F
225 HBW
P-No. 11
225 HBW
P-No. 15E
248 HBW
• Other alloy steels shall have a maximum harness of 22HRC(237HBW)
CNQ
PREMIUM VALUE | DEFINED GROWTH | INDEPENDENT
Slide 23
Hydrogen Bake out Temperature and Time
CNQ
PREMIUM VALUE | DEFINED GROWTH | INDEPENDENT
Slide 24
NACE MR 0103 Materials Resistant to Sulfide Stress
Cracking in Corrosive Petroleum Refining Environments
• Conclusions:
NACE MR0103 standard establishes material requirements for
resistance to Sulfide Stress Cracking (SSC) in sour petroleum
refining and is applicable to us.
The selection of materials for service in equipment used in oil and
gas production in H2S –containing environments is very important
because the failure could pose a risk to the health and safety of the
public and personnel.
Metallic materials selected using MR0103 are resistant to cracking
in defined H2S-containing environments ,but NOT NECESARILY
IMMUNE to cracking under all service condition.
It is the equipment user’s responsibility to select materials suitable
for the intended service!!!
CNQ
PREMIUM VALUE | DEFINED GROWTH | INDEPENDENT
Slide 25