1. PIPING MATERIAL MODULAR FABRICATION YARD PIPING MODULE – PART II

2. INTRODUCTION Piping Materials can be classified as
Metals (ferrous) : CS, SS, Alloy Steel
Metals (non-ferrous) : Cupro Nickel, Al
Non-metals : PVC, cement, glass
Materials are selected based on their mechanical and metallurgical properties.
Mechanical properties: strength, ductility, hardness, brittleness, toughness
Metallurgical properties: Chemical composition, weldability

3. CARBON STEEL Low Carbon Steel : C < 0.15%
Condenser Tubes : SA Weldability : Excellent
Mild Steel : 0.15% < C < 0.30%
Pipes : SA 106 GR B
Weldability: Good

4. CARBON STEEL Medium Carbon Steel : 0.3% < C < 0.5%
Machinery Parts
Weldability: Fair
High Carbon Steel : 0.5% < C < 1%
Dies & punch, Tools
Weldability: Poor
Steel : Carbon < 2%
Cast Iron : Carbon > 2%

5. Weldability
As Carbon % increases , weldability decreases
Effect of carbon & other elements on the weldability of carbon steels can be estimated by equating them to an equivalent amount of carbon.
Carbon Equivalent:
Ceq = C + Mn/6 + Cr + Mo+ V + Cu + Ni
Killed Steel
During Steel making process oxygen present is removed by adding Silica (De oxidizing agent).

12. ALLOY STEEL
Addition of elements such as Cromium, Nickel, Molybdenum, Manganese, Silicon along with heat treatment improves the properties of steels such as mechanical strength, corrosion resistance, toughness
Steel is a ferrous alloy having main constituent Iron and other alloying elements / Impurities like Carbon, Manganese, Phosphorus, Sulfur, Silicon, Chromium, Nickel, Molybdenum

13. ALLOY STEEL Solid solubility in ferrous alloys :
Interstitial solid solution :
Carbon with Iron forms interstitial solid solution
(Carbon steel)
Substitutional solid solution :
Cromium and Nickel with iron forms Substitutional solid solution (Stainless steel)
Low alloy steels :
Alloying elements < 5%
High alloy steels :
Alloying elements > 5%.

14. STAINLESS STEEL
Alloy of iron with Cromium content more than 11% and less than 30% and other alloying elements Nickel, Molybdenum etc is called stainless steel.
Stainless steel has excellent resistant to corrosion.
Stainless steel becomes corrosion resistant (passive) because of formation of un-reactive film which adheres tightly to the surface of metal. This can be chromium oxide (Cr2O3) film that acts as a barrier protecting metal against corrosion.

15. EFFECT OF ALLOYING ELEMENTS
Chromium : Increases resistance to Oxidation.
Nickel : Increases resistance to mineral acid,
produces tightly adhering high temperature oxides.
Molybdenum: Increases resistance to chloride.
Copper : Increases resistance to sulphuric acid.
Titanium : Stabilize carbides to prevent formation of chromium carbide
Niobium : Stabilize carbides to prevent formation of chromium carbide

18. STAINLESS STEEL Classification based on 1. Alloying Constituents
2. Metallurgical Microstructure
3. Degree of sensitization

19. STAINLESS STEEL Alloying constituents 200 Series : Cr. Ni - Mn group
( Mn replaces a portion of Ni)
300 Series : Cr - Ni group
400 Series : Straight Chromium Group
( Cr < 30%)

20. STAINLESS STEEL Metallurgical microstructure. Austenitic SS:
Alloy of Cr, Ni, Fe
Non Magnetic
High Corrosion resistance at temp up to 1500F
Hardenable by cold working
Crystallographic form-Face centered Cubic lattice (fine grain structure)
Possess high impact strength at low temp
Ex: Type 304, 304L,316,316L

21. STAINLESS STEEL Ferritic SS: Alloy of Cr, Fe Magnetic
Non Hardenable by heat treatment
Crystallographic form- Body centered cubic lattice (coarse grain structure)
For marine application. (10.5% Cr alloy with no nickel)
Contains high carbon, therefore brittle & relatively poor corrosion resistance
Has resistance to chlorides stress corrosion cracking
Ex: Type 409, 430, 439

22. STAINLESS STEEL Martensitic SS.
High hardness (carbon added to the alloy)
Corrosion resistant
Heat treatable to high hardness level
Crystallographic form-distorted lattice
Type 410,420.

23. STAINLESS STEEL Precipitation Hardened SS Magnetic
Heat treatable to high strength.
Weldable and corrosion resistant similar to type 304
Ex:-17-7PH, 17-4PH

24. STAINLESS STEEL Duplex SS
Contain both Austenite & Ferrite in microstructure. Ni (4 to 7%).
When ferrite- Resistant to chloride stress corrosion cracking.
When Austenite-Sensation to chloride stress corrosion cracking.
High strength, Good corrosion resistance
Ex: Alloy 2205, Alloy 255

25. STAINLESS STEEL 3. Degree of sensitization of grain boundaries GROUP 1
SS grade 304,316,309,310.
They are susceptible to sensitization. (During welding, flame cutting)

26. STAINLESS STEEL GROUP 2 Stabilized stainless steel type 321 &347
Grain boundaries sensitization eliminated by alloying elements like Titanium or Columbium. (Because Titanium or Columbium forms carbides first).
Columbium (Type 347) is stronger stabilizing agent than Ti (Type 321), Hence Type 347 is superior to 321

27. STAINLESS STEEL
GROUP 3
Extra low carbon stainless steel Type 304L, 316L
Can be stress relieved, welded & cooled slowly without significantly increasing their susceptibility to IGC.

29. ASTM / ASME Nomenclature
Materials are listed based on their known chemical composition, manufacturing processes, mechanical strength etc, in different codes i.e,ASTM, ASME, DIN, MSS etc, and common UNS number
ASTM Standard gives various details of materials like manufacturing process, Grades, Chemical Composition, and Mechanical Properties.
ASME Code accepts the ASTM materials with some additional specified properties.

30. ASTM / ASME Nomenclature
SA 312 TP 304
S : ASME approved Material
A : Ferrous
312 : Manufacturing Process No.
TP : Tubular Product
304 : Grade
SA 234 GR WPB
234 : Manufacturing Process No.
GR : Grade.
WP : Wrought Product
B : Grade

31. ASTM / ASME Nomenclature
SA 350 LF 2 : Low Temperature Forging Grade 2
SA 216 WCB : Weldable Casting Grade B
SA 335 P 11 : Pipe Grade 11
SA 182 Gr F11 : Forging Grade 11
SA 351 Gr CF 8 : Centrifugal Cast, Carbon % %
SA 351 Gr CF 3 : Centrifugal Cast, Carbon % %
SA 351 Gr CF 8M : Centrifugal Cast, Carbon % %, Mo
SA 351 Gr CF 3M : Centrifugal Cast, Carbon % %, Mo

32. CORROSION
Corrosion is the tendency of any metal to return to its most stable thermodynamic state i.e. state with most negative free energy formation. . More simply stated, it is a chemical reaction of metal with environment to form an oxide, carbonate, sulphate or other stable compound.
Corrosion is broadly classified into two categories:
Low temperature corrosion (corrosion at room temperature and below)
High temperature corrosion (corrosion at elevated temperature including molten metal.)

33. General or uniform corrosion. Localized Corrosion
Classification :
General or uniform corrosion.
Localized Corrosion
Inter granular corrosion (IGC)
Pitting corrosion
crevice corrosion
Stress corrosion cracking
Micro biological influenced corrosion.

34. INTER GRANULAR CORROSION
During Welding:- ( at Temp F ), Carbon molecules diffuse to grain boundary & precipitate out of solid solution as chromium carbide at the grain boundaries. This result in the depletion of chromium content in the thin envelope surrounding each grain, Hence Stainless Steel becomes susceptible to Inter Granular Corrosion & is said to be sensitized.
Corrosion property of sensitized steel can be restored by desensitization i.e. heat above 1600 F, & rapid cooling.
Testing Standard: IGC Practice A/B/C/D/E

35. SULPHIDE STRESS CORROSION CRACKING
A cracking process that requires simultaneous action of corrodant and sustained tensile stress.
Testing Standard: NACE TM- 01/77
Reporting of test result: Curve shall be reported as per NACE-TM for various stress level between 72%and 90% of SMYS.
Acceptance Criteria: At 72 % SMYS, time of failure shall not be less than 720 hrs.

36. HYDROGEN INDUCED CRACKING
Hydrogen induced cracking (HIC) is also known as cold cracking, delayed cracking or under bead cracking
HIC occurs in piping or vessel as a result of hydrogen pick up in service
It occurs in steels during steel manufacturing, during fabrication, and in service. It occurs as a result of welding, the cracks are sited either in HAZ of parent material or in the weld metal it self.
Testing Standard: NACE TM- 02/84

37. NACE NACE: National Association of Corrosion Engineers
NACE Standard gives chemical composition, Manufacture, Fabrication & testing Requirements for Steels intended to be used for Sour Service environment
Sour service Requirements
Steel shall be manufactured by Basic Oxygen Process or Electric arc furnace
Steel to be Killed & fine grained
Materials shall be in Normalized Condition
Nickel % limited to < 1%
Carbon content< 0 .23%
Carbon Equivalent < 0.43%
Hardness < 22 HRC
Sulpher content< 0.002%

38. Material Selection Criteria
Service media
Corrosive-sea water, H2S, Ammonia
Non Corrosive
Temperature
Cryogenic
Low temperature
Medium temperature
High temperature
Pressure
Low pressure
High pressure
Standard
Material specification
Additional requirements
Economy
Cost
Availability
Weldability
Manufacturability

39. Material Selection for Temperature
SERVICE
TEMPERATURE (°F)
PLATE
PIPE
FORGING
PRESSURE BOLTING C R Y O G E N I T M P
(-425) – (-321)
SA 240 types
304, 304L, 347
SA 312 types
304,304L, 347
SA 182 grades F304, F304L, F347
Bolts: SA 320 gr. B8 strain. Hardened
Nuts: SA 194 gr.8 (S5 SA 20)
(-320) – (-151)
SA 240 types 304, 340L, 316, 316L
SA 353
SA 312 types 304, 304L, 316, 316L
SA 182 grades F304, F304L, F316

40. Material Selection for Temperature (Continued…)
SERVICE
TEMPERATURE (°F)
PLATE
PIPE
FORGING
PRESSURE BOLTING L O W T E M P R A U
(-150) – (-76)
SA 203 GR.D OR E
SA 333 GR.3
SA 350 GR. LF3
BOLTS: SA 320 GR.L7
NUTS: SA 194 GR.4
(-75) – (-51)
SA 203 GR.A OR B
(-50) – (-21)
SA 516 ALL GRADES IMPACT TESTED
SA 333 GR.1
SA 350 GR. LF1 OR LF2
(-20) – (+4)
SA 516 ALL GRADES OVER 1 IN. THICK IMPACT TESTED
SA 53 (SEAMLESS) OR SA 106
BOLTS: SA 193 GR.B7
NUTS: SA 194 GR.2H
(+5) – (+32)

41. Material Selection for Temperature (Continued…)
SERVICE
TEMPERATURE (°F)
PLATE
PIPE
FORGING
PRESSURE BOLTING I N T E R M D A P
(+33) – (+60)
SA 285 GR.C, ¾ IN. THK. MAX.
SA 515 GR.55, 60, 65, 1.5IN. THK. MAX.
SA 516 ALL GRADES, ALL THK.
SA 53 (SEAM LESS) OR SA 106
SA 181 GR.I OR II
SA 105 GR.I OR 11
Bolts: SA 193 gr. B7
Nuts: SA 194 gr. 2H
(+61) – (+775)
SA 204 GR.B ALL

42. Material Selection for Temperature (Continued…)
SERVICE
TEMPERATURE (°F)
PLATE
PIPE
FORGING
PRESSURE BOLTING E L V A T D M P R U
(+776) – (+875)
SA 204 GR.B OR C
SA 335 GR.P1
SA 182 GR.F1
BOLTS: SA 193 GR.L7
NUTS: SA 194 GR.2H
(+876) – (+1000)
SA 387 GR.11 CL1
SA 387 GR.12 CL.1
SA 335 P11
SA 335 P12
SA 182 GR. F11
SA 182 GR. F12
(+1000)– (+1100)
SA 387 GR.22 CL1
SA 335 P22
SA 182 GR.22
SA 193 GR.B5
SA 194 GR.3
(+1100)– (+1500)
SA 240 TYPES 304, 316, 321, 347, 347PREFERED
SA 312 TYPES 304H, 316H, 312, 347H
SA 182 GRADES 304H, 316H, 321H, 347H
SA 193 GR.B8
SA 194 GR.8
ABOVE +1500
TYPE 310 STAINLESS INCOLOY

43. GROUPING OF MATERIALS Base Metal Type P1 : Carbon Steel
P3, P4,P5 : Alloy Steel
P6, P7 : Ferritic & Martensitic Steel
P8 : Austenitic Stainless Steel
P9 : Nickel Steel
P10, P11 : Quenched & Tempered Steel

44. MATERIAL AND ITS SPECIFICATIONS

45. THANK YOU