NACEMR

max
Æ Wrought S45000
– Single-step precipitation-hardening treatment – 31 HRC max
Slide 15
MR0175 - PH Martensitic Stainless Steels
Æ MR0175-2002
– Wrought S17400, Double-H1150 and H1150M conditions, 33 HRC maximum.
and CB7Cu-2
– Double-H1150 and H1150M conditions – 33 HRC max for wrought grades – 310 HBW (30 HRC) max for cast grades – S17400 and S15500 Bolting - H1150M only – 29 HRC
Æ MR0175-2002
– PWHT required for welding of low-alloy steels – Maximum hardness 22 HRC
Æ MR0175/ISO 15156
– Same requirements as for carbon steels – Would allow welding w/o PWHT where allowed by construction
or – Free water pH > 7.6 and > 20 ppmw hydrogen
cyanide ion (HCN) and some H2S dissolved in the free water , or – >0.0003 MPa abs (0.05 psia) partial pressure H2S in a process with a gas phase
– MR0175/ISO 15156 low-alloy steel: steel with a total alloying element content of less than about 5%, nickel < 1%
Æ Hardness Requirements in MR0103
– P-No.’s 3, 4, 10, 11 - 225 HB max – P-No.’s 5A, 5B, 5C, 6, 7 - 235 HB max – P-No. 5B 9Cr-1Mo-V grades - 248 HB max – Other alloy steels – 22 HRC max
Why Create a New Document? Æ Lack of refinery-specific standard for materials
resistant to sulfide stress cracking Æ Methods of applying MR0175 within the refining
Slide 12
Page 2
Welding of Alloy Steel
Æ MR0103
– Allows welding of P-No.’s 3 and 4 without PWHT where allowed by ANSI/NB-23
– Hardness traverse required – 248 HV maximum
environment is "sour"
Æ Environmental restrictions on materials
Æ Materials and/or material conditions included
Æ Welding controls
Upstream vs. Downstream Sour Environments
Slide 6
Page 1
Application of Requirements
Æ Both MR0175 and MR0103
– User is responsible for deciding whether the material requirements of the standard need to be applied
– PWHT, or
– Base metal chemistry controls, or
– HAZ hardness traverse on PQR specimen (248 HV max) combined with weld parameter and chemistry controls
Slide 9
codes – Hardness traverse required – 250 HV maximum
Slide 13
Martensitic Stainless Steels
Æ Requirements are essentially the same for MR0103, MR0175-2002, and MR0175-2003
– Hardness traverse on PQR specimen (250 HV max), but
– No PQR/Production chemistry controls
Slide 11
Aln
– MR0103: steel with a chromium content of less than 10%
Æ RP0472 Weld Deposit Hardness Controls
– Deposit hardness testing
• Exemptions: SMAW with E70XX fillers GTAW with ER70S-X (except -6, -7, or –G)
Æ RP0472 Base Metal HAZ Hardness Controls
2 base materials Æ 22 HRC maximum on other carbon steels
Slide 8
Welding of Carbon Steel
Æ MR0103 - welds in P-No. 1 carbon steels must be performed per NACE Standard RP0472
Æ Often contain cyanides
Æ Seldom contain chlorides or CO2
Slide 3
Slide 4
MR0103 Application Approach
Æ Focuses on the broader range of sour environment conditions experienced in downstream process units
Slide 5
MR0103 Guideline - Sour Service Definition
Æ Free water in the liquid phase and:
– >50 ppmw dissolved H2S in the free water, or – Free water pH < 4 and some dissolved H2S present,
• Cannot locate deposits for hardness testing
– Most foundries use multiple processes/filler grades
• Don’t know which process was used
– Result
• May require special-order purchase of castings with RP0472 requirements imposed
– Wrought S45000, single-step precipitation-hardening treatment , 31 HRC maximum
– Cast CB7Cu-1 in Double-H1150 condition, 310 HBW (30 HRC) max, for non-pressure-containing, internal valve, and pressure regulator components only.
Welding of Carbon Steel (continued)
Æ Impact of MR0103 (RP0472) vs. MR0175
– Mainly affects cast steel components (pump casings, valve bodies, etc.)
– Weld repairs on commercial castings not mapped
Slide 10
Welding of Carbon Steel (continued)
Æ MR0175-2002 welding requirements much less specific
Æ MR0175/ISO 15156 requirements improved, but still much less specific than RP0472
Upstream Æ Often contain CO2, which
causes low pH.
Downstream
Æ Often contain dissolved ammonia
Æ Often contain chlorides, which can cause chlorideion stress corrosion cracking.
Introduction to NACE MR0103 and Comparison with
NACE MR0175/ISO 15156