SHAWN HSU12/22 /2012

NACE MR0175/MR0103 主要差異與其關聯簡稱

Outline

1. NACE Brief Introduction and its history2. MR0175/ISO 15156, MR0103. comparison

and description 3. Carbon steel and other alloy (Austenltic,

Martensite ) criterion 4. The Corrosion feature of steel in

petroleum and refinery industry 5. Other related term sketch (Cracking,

Hardness, Strength and Welding) 6. Summary

1. NACE Brief Introduction

Goal: Protecting people, assets and the environment from the effects of corrosion.

Seeking : Education, Establish, Promote, Advocate

Founding : 11 engineers establish the association which solely focused from cathode protection to material selection and design in all kind of industries.

Training: Originally, NACE was training un-experienced or no background people, then developes to confer the experienced persons for advanced training.

Founding Member

1. NACE Brief Introduction

Technical Committees

W.R. Whitney Award

Propose

Ballot (every spring)

New Material Add

All Positive

One Reject

NACE Chairman approve

NACE monthly publication (MP)

1. NACE Brief Introduction

Annual Conference NACE Certification

Quotation

Mars Fontana once said that : solving a corrosion problem involved 25% knowledge, 50% experience, and 25% luck.

Evolution

membership

1. NACE Brief Introduction

Hydrogen Embrittlement : is the process by which metal, most high-strength steel, become brittle and

fracture following exposure to hydrogen. Counteraction: 1. De-Hydrogenation 2. Hydrogen killer 3. Inhabitation doping

NACE MR 0175/MR 0103

MR : Material Requirement 01 : version number75/03 : 1975 / 2003 yearScope: MR0175upstream (Oil & Gas

production) MR0103downstream (refining

and Gas production) Target: Control sour service environment

which includes H2S to select resistance of SSC (Sulfide Stress Cracking) material

Major Difference between MR0103 & MR0175: 1. The refinery standard guidelines for

determining whether an environment is “ sour” are quite different from the version of MR0175

2. The refinery standard does not include environment restriction on material

3. Ammonia’s concentration in downstream is higher than upstream so it will increase solubility of H2S

4. Because welding is prevalent in refinery piping and equipment, MR0103 would put emphasis on controlling it, especially carbon steel.

NACE MR 0175/MR 0103

MR0175 sour service

MR0175: All gas phase, condense and oil within H2S

equal or over 0.05psia should apply. (Total pressure should over limitation)

Single gas phase

Multi phase (gas, oil, water..)

MR0103 sour service

MR0103: 1. >50ppmw dissolved H2S in the free water 2. A free water PH<4 and some dissolved H2S present 3. A free water PH>7.6 and >20ppmw hydrogen cyanide ion and some H2S dissolved in the free water 4. >0.05 psia partial pressure H2S in a process with gas phase (no limitation)

NACE MR0175/MR0103

MR0103 cover a broad range of sour service so guideline are based on:

1.User’s plant experience and practices 2.Existing NACE and industry recommended practice and reports 3.A fundamental theory of atomic hydrogen generation in sour service area.

**User would be allowed supply their own experience or risky analysis to determine plant operating scenarios

H2S impact in production area

H2S leads to SSC(Sulfide Stress Cracking)SSC impacting factors: 1. Metal Feature (composition, strength, microstructure ) 2. Environment PH value 3. H2S concentration and partial pressure 4. Temperature & Exposure time

Impacting Factor

PH value: Acid concentration in refinery area is lower than oil production.

H2S partial pressure: It is over 0.05 psia or 50 ppmw apply the NACE code.

C.S.

5Cr-0.5Mo Alloy

A.S.

Temperature: Hydrogen ion would dissolve easily in high temperature Brittle as cool down

Exposure time: More uncover more chance to corrosion

Impacting Factor

Related term sketch

SSC (Sulfide Stress Cracking): It is a form of Hydrogen Embrittlement. Alloy would form metal sulfide and atomic hydrogen as corrosion by product.

HIC (Hydrogen Induce Cracking): H2S encounter with steel to form surface blister and diffuse to internal site then trapped. With more H+ accumulating, the stress increase to cross boundary line.

Fe + H2S FeS + 2H+

2H+ + 2e- H2 (g)

Cracking

SCC(Stress Corrosion Cracking): is the cracking induced from the combined influence of tensile stress and a corrosive environment. Model: Step-Wise Cracking

Cracking

Hardness & Strength

Tensile Strength: is the maximum stress that material withstand while being stretched or pulled before necking

Yield Strength: the point as the stress at which a material begins to deform plastically.

Hardness & Strength

Brinell Hardness:

Rockwell Hardness: F0+F1 on test material (9 scale: HRX)

Vicker’s Hardness:

Conversion: ASTM E140 table

Welding

HAZ(Heat Affecting Zone): The area which execute welding and then subsequently re-cooling process causes the heat energy diffuse to lower zone, until terminate to temperature sensitivity area.

WPQ(Welding Performance Qualification):is a kind of process to evaluate the welding performance.

Welding

PWHT(Post Welding Heat Treatment): is stress relief and a kind of method for reducing and redistributing residual stress by welding.

PERN: %chromium+3.3X%molybdenum+(16 to 30)X% nitrogen.

Chromium: Increase oxidation ability and corrosion

Molybdenum: Help Cr stable and increase hardness

Nitrogen: Stabilize lattice structure and increase the

mechanical property

NACE MR0175 & MR0103 Requirement

Category MR0175 / ISO 15156 MR0103

Carbon Steel

Max Hardness: HRC 22Conditions: Annealed, Normalized, Normalized & Tempered, Quenched & Tempered, Stress RelievedWelding: Vickers Hardness survey regardless of whether PWHT or notSuggestion regarding "other controls" detected.

Max Hardness: HRC 22Conditions: Annealed, Normalized, Normalized & Tempered, Quenched & TemperedWelding: Vickers Hardness survey regardless of whether PWHT or notSuggestion regarding "other controls" detected.

Alloy Steel

Max Hardness: HRC 22Conditions: Annealed, Normalized, Normalized&Tempered, Quenched&Tempered,Stress RelievedWelding: Vickers Hardness suvey regardless of wheather PWHT or not

Max Hardness: For P numbered steel Conditions: Annealed, Normalized&Tempered, Quenched&TemperedWelding: Vickers Hardness suvey regardless of wheather PWHT or not

Austenitic StainlessMax Hardness: HRC 22Conditions: Solution Heat TreatedWelding: Vickers Hardness suvey

Max Hardness: HRC 22Conditions: Solution Heat TreatedWelding: No specific control

Martensitic Stainless

Max Hardness: HRC 22Conditions: Annealed, Normalized, Normalized&Tempered, Quenched&Tempered,Stress RelievedWelding: Vickers Hardness suvey

Max Hardness: HRC 22Conditions: Quenched & Double-TemperedWelding: No specific controlSuggestion regarding "other controls" detected.

Steel Category definition

Carbon Steel content: Carbon content(<2%), Manganese (<0.25%), no requirement for other metal element.

Low Carbon Steel (0.16%~0.29%):Medium Carbon Steel(0.3%~0.59%):High Carbon Steel(0.6%~0.99%): Alloy Steel: Generally define chromium

content less than 10% and total alloying element content exceed 10%. MR0175 especially notify nickel content because nickel would reduce the resistance of SSC

Steel Category definition

Austenitic Stainless content (FCC): C(<0.15%),Cr(>16%),Ni(8%),Manganese(<2%),Silicon(<2%), Major item stainless in industry.

Martensitic Stainless content (BCC): Cr(12~14%),Mo(0.2~1%),Ni(<2%),C(~1%) :Magnetic& strong.

Austenitic

Martensitic

Heat Treatment

Anneal : is a kind of heat treatment that material would be altered its properties like hardness and ductility. Re-crystallized distorted structure.

Normalized : is an annealing process in which a metal is cooled in air after heating for relieving stress.

Quenched : it is the rapid cooling of workforce to obtain material properties. Like strength and hardness of iron-based alloy.

Tempered : it uses to increase toughness of iron-based alloy and usually combine with Quenched process.

Corrosion in oilfield

Because the H2S will dissolve into H2 & S which will combine with H2O around the environment and generate H2SO4 and HCl. Then these two chemical compounds will react with metal and corrode.

Corrosion in oilfield

2HCl (aq)+Fe (s) FeCl2+H2(g)

**Pickling agent: It is an important application by using hydrogen acid to remove rust or iron oxide scale : Fe2O3+Fe+6HCl 3FeCl2+3H2OTypically 18% concentration

NACE code use to define material selection to resistance SSC feature and H2S corrosion.

H2S would cause outer & internal damage of steel in upstream or downstream.

Internal corrosion: SSC, HIC,SCC….. Outer corrosion: Hydrogen acid, Sulfide acid

corrosion Effectively control H2S environment or

correctly select material for equipment or related facility.

Summary

Q&A:

Thank you for your attention