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 179
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
5 15
Killed Steel
During Steel making process oxygen present is removed
by adding Silica (De oxidizing agent).
6.
7.
8.
9.
10.
11.
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
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.
28. 1) Austenitic SS
Type 304 S 30,400 75,000 30,000 30 29,000,000 80 RB
Type 304L S 30,403 70,000 25,000 35 29,000,000 75 RB
Type 316 S 31,600 75,000 30,000 30 28,000,000 80 RB
Type 316 L S 31,603 70,000 25,000 35 28,000,000 75 RB
2) Ferritic SS
Type 430 S 43,000 60,000 30,000 20 29,000,000 85 RB
Type 439 S 43,035 60,000 30,000 20 29,000,000 90 RB
Type 409 S 40,900 55,000 30,000 20 29,000,000 85 RB
3) Duplex SS
Alloy 2205 S 31,805 90,000 65,000 25 29,000,000 30 RC
70 Mo Plus S 32,950 90,000 70,000 20 29,000,000 30 RC
Alloy 255 S 32,550 1,10,000 80,000 15 30,500,000 32 RC
4) Martensitic SS
Type 410 S 41,000 1,90,000 1,50,000 15 29,000,000 41 RC
Type 420 S 42,000 2,40,000 2,00,000 5 29,000,000 55 RC
Type 440L S 44,050 2,80,000 2,70,000 2 29,000,000 60 RC
5) Precipitatim SS
17.7 PH S 17,700 2,10,000 1,90,000 5 32,500,000 48 RC
17.4 PH S 17,400 1,90,000 1,70,000 8 28,000,000 45 RC
Custom 455 S 45,500 2,30,000 2,20,000 10 29,000,000 48 RC
ALLOYS UNS NO HARDNESS
PROPERTIES OF STAINLESS STEEL ALLOYS
Elongation
(%) min
YS
( PSI)
UTS
(PSI)
MODULUS
OF
ELASTICITY
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
S : ASME approved Material
A : Ferrous
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 % - 0.08%
SA 351 Gr CF 3 : Centrifugal Cast, Carbon % - 0.03%
SA 351 Gr CF 8M : Centrifugal Cast, Carbon % - 0.08%, Mo
SA 351 Gr CF 3M : Centrifugal Cast, Carbon % - 0.03%, 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.)
34. INTER GRANULAR CORROSION
During Welding:- ( at Temp. 800-1600 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-01-77 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
C
T
E
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
E
R
A
T
U
R
E
(-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 SA 333 GR.3 SA 350 GR.
LF3
(-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) SA 516 ALL
GRADES OVER 1 IN.
THICK IMPACT
TESTED
41. Material Selection for Temperature (Continued…)
SERVICE
TEMPERATURE (°F) PLATE PIPE FORGING
PRESSURE
BOLTING
I
N
T
E
R
M
E
D
I
A
T
E
T
E
M
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 285 GR.C, ¾ IN.
THK. MAX.
SA 515 GR.55, 60,
65, 1.5IN. THK. MAX.
SA 516 ALL
GRADES, ALL THK.
SA 204 GR.B ALL
42. Material Selection for Temperature (Continued…)
SERVICE
TEMPERATURE (°F)
PLATE PIPE FORGING
PRESSURE
BOLTING
E
L
E
V
A
T
E
D
T
E
M
P
E
R
A
T
U
R
E
(+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
DESCRIPTION CS AS SS DSS
PIPE A 106 GR B A 335 GR P11 A 312 TP 316 A 790 UNS S31803
BW FITTINGS A 234 GR WPB A 234 GR WP 11 A 403 WP 316 A 815 UNS S 31803
FORGED
FLANGES/
FITTINGS
A 105 A 182 GR F11 A 182 GR F 316 A 182 GR F 51
UNS S 31803
FASTNERS A 193 GR B7/
A 194 GR 2H
A 193 GR B16/
A 194 GR 2H
A 193 GR B7M/
A 194 GR 2HM
A 453 GR 660 CL A
PLATES A 516 GR 70 A 387 GR 11 A 240 GR 316 A 240 UNS S 31803