Engineering Standard 10 January 2022

SAES-W-016
Welding of Special Corrosion-resistant Materials
Document Responsibility: Welding Standards Committee

Previous Issue: 20 February 2019 Next Planned Update: 10 January 2027

Page 1 of 20
Contact: (GHAMTA0E)

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 Document Responsibility: Welding Standards Committee SAES-W-016
Issue Date: 10 January 2022
Next Planned Update: 10 January 2027 Welding of Special Corrosion-resistant Materials

Contents

Summary of changes .................................................................................................... 3

1 Scope ...................................................................................................................... 5

2 Conflicts and Deviations .......................................................................................... 5

3 References .............................................................................................................. 6

4 General ................................................................................................................... 7

5 High Temperature Applications ............................................................................... 8

6 Corrosive Services .................................................................................................. 9

7 Special Requirements for Lean Duplex, Duplex and

Super Duplex Stainless Steels .............................................................................. 14

8 special requirements for titanium and its alloys ..................................................... 16

Revision Summary ...................................................................................................... 19

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 Document Responsibility: Welding Standards Committee SAES-W-016
Issue Date: 10 January 2022
Next Planned Update: 10 January 2027 Welding of Special Corrosion-resistant Materials

Summary of Changes

Paragraph Number
Change Type
Technical Change(s)
Previous Revision Current Revision (Addition, Modification, Deletion,
New)
(20 February 2019) (10 January 2022)

3.2 3.2 Addition New standard ASTM A1084 is

added for lean duplex
stainless steels

NA 5.3 New Sulfur content requrment for

super austenetic steel in line
with IOGP S-705.

7.1.1 7.1.1 Modification UNS S31803 and UNS

S32205 are interchangeable in
line with IOGP S-705.

NA 7.1.4 New Change in position for

procedure qualication is
considerd essential variable in
line with IOGP S-705.

NA 7.1.5 New Change in metal transfer

mode for procedure
qualication is considerd
essential variable in line with
IOGP S-705.

7.1.6 7.1.8 Addition Corrosion test rquirmet is

added for lean duplex
stainless steel

NA 7.1.9 New New requirements for welding

duplex stainless steel
thickness qualfiation to be
aligned with IOGP S-705

7.1.7 7.1.10 Modification Impact test temperatur for

duplex stainless steel is
modified to be aligned with
IOGP S-705.

NA 7.1.11 New This paragraph was included

udner section 7.1.7. New
separate section is made for
heat input requirment.

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 Document Responsibility: Welding Standards Committee SAES-W-016
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Next Planned Update: 10 January 2027 Welding of Special Corrosion-resistant Materials

Paragraph Number
Change Type
Technical Change(s)
Previous Revision Current Revision (Addition, Modification, Deletion,
New)
(20 February 2019) (10 January 2022)

NA 7.1.14 New PREN requirment for duplex

and super duplex stainless
steel to be aligned with IOGP
S-705.

NA 8.1.6 New Change in position for

procedure qualication for Ti
allots is considerd essential
variable in line with IOGP S-
705.

NA 8.1.7 New Change in metal transfer

mode for procedure
qualication for Ti alloys is
considerd essential variable in
line with IOGP S-705.

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 Document Responsibility: Welding Standards Committee SAES-W-016
Issue Date: 10 January 2022
Next Planned Update: 10 January 2027 Welding of Special Corrosion-resistant Materials

1 Scope

1.1 This standard specifies the requirements for welding and testing of special
corrosion-resistant materials of pipelines, on-plot pipes, pressure vessels and
heat exchangers. This is defined as stainless steel, nickel-based alloys and
titanium or titanium alloys in severe corrosion service or/and high temperature
service, as defined below.

1.1.1 Severe corrosion service is defined as:

a) Any service listed in SAES-L-132 which specifies the use of
austenitic stainless steel (excluding types 316/316L) or nickel-
based alloys or titanium or titanium alloys.
b) Any service that uses duplex stainless steels.
Note:
Use of stainless steel or nickel-based alloys for product cleanliness
(e.g., lube oil piping or aircraft refueling facilities) or mechanical properties (e.g., low
temperature service requiring impact toughness) are not included.
1.1.2 High temperature service is defined as any application with a design
temperature above 400°C (750 °F).
1.1.3 Additional requirements for duplex stainless steel and
titanium/titanium alloys for any service are included.
1.1.4 Strip lining and weld overlay applications are not included.
Note:
Refer to SAES-W-014 for welding requirements for overlays and SAES-W-015 for strip lining
requirements.
1.1.5 This standard is to be considered as a supplement to other Saudi
Aramco welding standards. Other applications (e.g., valves or
pumps) may also be subject to this standard if the application
standard or job specification makes reference to this standard.
1.1.6 These requirements are in addition to the requirements of ASME SEC
IX.
1.2 This entire standard may be attached to and made part of purchase orders.

1.3 Additional requirements may be contained in Scopes of Work, Drawings, or

other Instructions or Specifications pertaining to specific items of work.

2 Conflicts and Deviations

Any conflicts between this document and other applicable Mandatory Saudi
Aramco Engineering Requirements (MSAERs) shall be addressed to the
EK&RD Manager.
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Any deviation from the requirements herein shall follow internal company
procedure SAEP-302.

3 References

All referenced specifications, standards, codes, drawings, and similar material

are considered part of this engineering standard to the extent specified,
applying the latest version, unless otherwise stated.

3.1 Saudi Aramco References

Saudi Aramco Engineering Procedure

SAEP-302 Waiver of a Mandatory Saudi Aramco Engineering

Requirement

Saudi Aramco Engineering Standards

SAES-L-132 Material Selection for Piping Systems

SAES-W-010 Welding Requirements for Pressure Vessels
SAES-W-011 Welding Requirements for On-plot Piping
SAES-W-012 Welding Requirements for Pipelines
SAES-W-014 Weld Overlays and Welding of Clad Materials
SAES-W-015 Strip Lining Application

Saudi Aramco Standard Drawing

AB-036386 Hardness Testing for Welding Procedure Qualifications

Saudi Aramco Best Practice

SABP-A-001 Polythionic Acid SCC Mitigation - Materials Selection and

Effective Protection of Austenitic Stainless Steels and other
Austenitic Alloys

3.2 Industry Codes and Standards

American Petroleum Institute

API TR 938-C Use of Duplex Stainless Steels in the Oil Refining Industry

American Society of Mechanical Engineers

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 Document Responsibility: Welding Standards Committee SAES-W-016
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ASME B31.3 Process Piping

ASME SEC IIC Specifications for Welding Rods, Electrodes, and Filler
Metals
ASME SEC V Nondestructive Examination
ASME SEC IX Qualification Standard for Welding and Brazing
Procedures, Welders, Brazers, and Welding and Brazing
Operators

ASTM International

ASTM A833 Indentation Hardness of Metallic Materials by Comparison

Hardness Testers
ASTM A923 Standard Test Methods for Detecting Detrimental
Intermetallic Phase in Duplex Austenitic / Ferritic Stainless
Steels
ASTM A1084 Standard Test Method for Detecting Detrimental Phases in
Lean Duplex Austenitic / Ferritic Stainless Steels
ASTM E140 Hardness Conversion Tables for Metals
ASTM E562 Standard Test Method for Determining Volume Fraction by
Systematic Manual Point Count

American Welding Society

AWS A4.2 Standard Procedures for Calibrating Magnetic Instruments

to Measure the Delta Ferrite Content of Austenitic and
Duplex Austenitic-Ferritic Stainless Steel Weld Metal
AWS G2.4/G2.4M Standard Guide for the Fusion Welding of Titanium and
Titanium Alloys

National Association of Corrosion Engineers/International Organization for

Standardization

NACE MR0175/ISO 15156

Petroleum and Natural Gas Industries-Materials for use in

H2S-Containing Environments in Oil and Gas Production

4 General

4.1 All welding procedures shall be qualified in accordance with ASME SEC IX plus
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Next Planned Update: 10 January 2027 Welding of Special Corrosion-resistant Materials

the additional requirements of SAES-W-010, SAES-W-011, SAES-W-012, as

applicable, and this standard.

4.2 Ferrite measurement for stainless steel welds shall be performed using point
count technique as per ASTM E562 for welding procedure qualification.
AWS A4.2 shall be used for verification in production welding.

4.3 Abrasive tooling and/or grinding disks shall not have been used on either
carbon steel or any other grade of stainless steel material. The selection of
grinding and cleaning tools shall be appropriate for the base material, e.g.,
carbon steel brushes shall not be used on stainless steel material.
Note:
During welding or heat treatment of stainless steel and duplex stainless steel, if zinc is present
in the weld area, Liquid Metal Embrittlement (LME) can lead to cracking.
4.4 All filler materials shall be individually and clearly stamped, flagged or stenciled
to ensure traceability and correct usage on site. Precautions shall be taken
throughout storage, conditioning and fabrication to minimize contamination of
corrosion-resistant alloy (CRA) consumables resulting from direct contact with
carbon and low alloy steels.

4.5 Handling & storage of base materials: All necessary precautions shall be taken
throughout fabrication to minimize contamination of CRA materials resulting
from direct contact with carbon steels, exposure to ferrous dust, swarf or other
debris and from residual deposits on or near fusion faces during welding.
Supports, rollers and other pipe handling equipment shall be of compatible
material or shall be suitably lined to prevent damage or contamination.

5 High Temperature Applications

5.1 The welding procedure qualification for austenitic stainless steels, except type
310 and 6% Mo super-austenitic stainless steel, shall include a determination of
the Ferrite Number in the as-welded condition. The Ferrite Number shall be
between 3 and 10 FN.

5.2 For production welds, the ferrite content shall be checked in the as-welded
condition. The Ferrite Number shall be between 3 and 10 FN.

5.3 For super austenitic stainless steels 6% Mo and 904L, the consumable shall
have a sulfur content not exceeding 0.015 %.

5.4 Any welding on high carbon grades of austenitic stainless steel material
(e.g., 304H or HK40) after service times exceeding 1 year shall require a
re-solution heat treatment prior to welding.

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5.5 Welds for high temperature service above 400οC (750 °F) with stabilized grades
shall be subject to thermal stabilizing post weld heat treatment. This shall also
apply for cold worked parts in such grades and applications.
Note:
Refer to SABP-A-001 for guidance. The above requirement applies for manufacturing and
shop fabrication. For field welds, the requirement shall apply if mandated by licensor and if
nitrogen purging or soda ash neutralization is not applied during shut down and if the service
environment contains S or H2S. Any such cases shall be submitted through the welding
procedure specification review process with detailed evaluation for CSD approval.
6 Corrosive Services

6.1 The GTAW process shall be used for the following applications:

6.1.1 The root pass of single-sided groove welds without backing.

6.1.2 For all passes for piping, tubes, and nozzles of 2 inch (50.8 mm)
nominal diameter or less.
6.1.3 For all passes for wall thickness less than 9.5 mm for duplex stainless
steel or for wall thickness less than 6.5 mm for other Corrosion
Resistant Alloys (CRA).
6.1.4 For all passes and wall thicknesses for Titanium and its alloys.
6.2 All manual GTAW shall use a high frequency start and post-purge gas flow for
the torch. A remote current control (pedal or torch mounted) is required. Pre-set
power source current start/rise and decay/stop controls triggered by a foot switch
or torch mounted control is an acceptable alternative for the remote control.

6.3 For all GTAW welding, filler metal shall be added. Autogenous welding of any
pass is not permitted.

The filler metal shall be of matching grade and composition as the base metal
with the exception of alloys listed Table 1. The approval of alternate
consumables shall be through the WPS review process.

6.4 Preheating, if used to remove moisture, shall be carried out with lamps,
resistance heaters, or induction heating equipment or dry air. The maximum
interpass temperature during welding of austenitic stainless steel and nickel
alloy materials shall not exceed 175°C (350 °F).
6.5 Purging for welding of stainless steels and Ni-based alloys shall be done as
follows:
6.5.1 An inert backing gas shall be used for GTAW or GMAW on single-
sided groove welds.

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6.5.2 During pre-weld purging, the joint area shall be adequately sealed at
all openings to maintain the purge and prevent any air ingress.
6.5.3 The purge times for the backing gas shall be calculated to give a
theoretical volume change of 6 times the enclosed pipe volume.
Table 2 is shown for information and can be used for the standard
conditions as listed in the table. Extra purging time is necessary if the
purge gas inlet and outlet (vent) cannot be placed at opposite ends of
the enclosed volume in order to insure complete displacement of the
original air.
Note:
During welding, the purging flow rate shall be appropriate to ensure that there is no
positive pressure on the root and hence absence of any root suck back.
6.5.4 Purging shall be maintained for at least three passes or 10 mm weld
metal thickness, whichever is higher. Welding of external attachments
(including reinforcement pad or sleeve) and seal welding, with wall
thickness less than 10mm shall not be conducted without back-
purging.
6.5.5 The purge shall achieve actual oxygen levels inside or exiting the
joint (via the vent) no greater than 0.05% prior to and during welding,
as measured using an oxygen analyzer. The actual oxygen levels
achieved in production shall be measured periodically (i.e., on a
random basis for the number of joints to be performed). Analyzers
shall be used for all joints if excessive internal oxidation is observed
on any joints based on the visual appearance of the oxide tint.
Analyzers shall be calibrated as per manufacturer recommendations
and copy of calibration certificate shall be available for
reference/verification by inspector, if required.
6.5.6 During pre-weld purging, the joint area shall be adequately sealed at
all openings to maintain the purge and prevent any air ingress.
6.5.7 If purge dams are to be used but cannot be retrieved after welding,
then proprietary dissolvable (water soluble) dams shall be used.
Note:
The contractor shall ensure that in that case, on dissolution, the purge dams do not
increase chloride content in water to or beyond the maximum limit specified for
hydrotest. The contractor shall also ensure that any residue left behind does not
cause fouling of any valves in the piping system during or after hydrotest.
6.5.8 Shop fabrication of stainless steel piping shall be maximized.
Shop fabrication welds shall be subject to internal visual inspection to
the extent specified in paragraph 6.9.1.
6.5.9 Purging shall be carried out for partial thickness repairs in stainless
steel, when the remaining ligament after the removal of the defect is
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less than 10 mm. Root or through-thickness repairs of stainless steel

groove welds in the field are not permitted, unless purging is carried
out.
6.5.10 The entire piping spool/circuit shall be purged with backing gas for
root or through-thickness repairs of stainless steel groove welds in
the field.
Note:
Alternatively, insertion of a pup-piece with purging using water soluble dams may
be considered.
6.6 Joint Design
For GTAW, the root gaps must be specified and maintained during welding at
equal to or larger than the root pass filler wire diameter.

Maximum internal misalignment between pipe or tube sections shall not exceed
1.6 mm.

6.7 Tacking
A minimum of 4 equi-spaced tacks around a pipe circumference shall be used.

Either root tacks or bridge tacks are permitted. Root tacks shall be welded in
accordance with the approved WPS for welding the joint using qualified
welders. Root tacks must be either feathered or ground out prior to making the
root pass. The requirements for purging in paragraph 6.5 shall also apply for
any tacks that are incorporated in the weld root (root tacks).

6.8 Technique
Either high frequency (HF) or high voltage (HV) arc initiation shall be used.

The continuous feed technique shall be used for the root pass (i.e., the filler
wire is positioned between the root faces and fed continuously into the weld
pool).
Note:
The welder must avoid narrow root gaps and improper travel speeds in order to achieve the
proper root bead deposit chemistry.
Stringer beads shall be used. Minor arc oscillation to ensure sidewall fusion is
permitted.

Whenever the welder stops welding, the welding current shall be gradually
decreased by use of the remote current control. The torch shall be held in
position close to the weld pool until the gas shielding post-purge flow is
completed.

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Grinding of all start/stops is required.

Note:
The maximum interpass temperature needs to be monitored regularly by the welder.
6.9 Inspection
6.9.1 Visual Inspection
a) All weld surfaces and heat affected zones must be free of dark
colored and heavy 'sugary' oxidization, pinholes, cracks, crevices,
undercut, lack of penetration, and incomplete fusion.

b) If the root ID surface can be visually inspected, the stop/starts shall

be examined. No crater defects, such as cracks, “suck-back,” or
shrinkage, are permitted. The general criteria listed above shall also
be met.

c) Where inaccessible for direct visual inspection of root area, 10% of

butt welds in stainless steel material, shall be examined using
suitable remote visual inspection (RVI) equipment –
e.g., borescope, videoscope, etc. Examination shall include weld and
discoloration levels in HAZ. Sugaring of weld root is not acceptable.

d) 10% visual examination of internal surface shall be carried out for

external attachment welds on stainless steel piping with wall
thickness less than 10 mm.
Note:
Target discoloration level for RVI as per paragraphs 6.9.1.3 and 6.9.1.4 is No.6, AWS D18.2 or
better.

6.9.2 Penetrant Testing

Dye penetrant testing is to be carried out after repair excavations and
completion of all root passes on both production and repair welds.
Dye penetrant testing must also be carried out on any surface where
attachment welds have been removed.

6.9.3 Radiographic Examination

Radiography is required on all production and repair welds. The
acceptance criterion shall be in accordance with the ASME B31.3
'Normal Fluid Service' category with the additional requirements of:

• Zero lack of root penetration.

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• Zero lack of root fusion

a) ASME SEC V, Article 2 shall be used to determine the minimum

number and required locations of radiographs for circumferential
joints.

b) Fluorescent intensifying screens shall not be used.

Fluoro-metallic screens shall be approved by Saudi Aramco
Inspection prior to use.

c) All field radiographic exposures (vendor, shop, and yard

radiography are exempt) shall be performed using at least two
people, a SAEP-1140 or SAEP-1142 qualified Level II
radiographer and an assistant who is qualified to operate all of
the equipment.

d) If the joint is required to be radiographed and radiography is

not feasible; then, computerized advanced ultrasonic methods
that produce a permanent record can be used in lieu of
radiography. The application of ultrasonic testing shall be
approved by the Inspection Department.

6.9.4 Ultrasonic Testing

When ultrasonic testing is utilized for examination of welds in lieu of
radiography the following criteria apply:

a) Ultrasonic testing shall be performed in accordance with

ASME SEC V Article 4 using computerized advanced ultrasonic
methods that produce a permanent record.

b) Ultrasonic examination of welds in material less than 1 inch

(25.4 mm) in thickness shall be conducted in accordance with
ASME B31.3 and ASME SEC V Article 4 Mandatory Appendix IX.

c) Ultrasonic examination of welds in material equal or greater than 1

inch (25.4 mm) in thickness shall be conducted in accordance with
ASME B31.3 or using Code Case 181 alternate acceptance
criteria.

d) Ultrasonic equipment, techniques, technicians, and procedures

shall be approved by the Inspection Department.

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 Document Responsibility: Welding Standards Committee SAES-W-016
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7 Special Requirements for Lean Duplex, Duplex and Super Duplex

Stainless Steels

The following requirements are in addition to all requirements previously

specified in this standard.
Note:
Duplex Stainless Steel alloys can be classified into three main groups: lean duplex, 22%Cr duplex
and 25%Cr super duplex grades. Requirements of base material properties such as PREN shall be
complied to SAES-L-132.
7.1 Qualification of welding procedures shall include the following
supplementary essential variables and testing requirements:

7.1.1 The base metal UNS number shall be considered an essential

variable, except that UNS S31803 and UNS S32205 are
interchangeable.
7.1.2 The size of the filler wire used in welding the root pass of the test
coupon is considered an essential variable.
7.1.3 The pitting resistance equivalent number (PREN) for 22Cr Duplex
and 25Cr Duplex filler metals shall be 34 ≤ PREN ≤ 40 and 40 ≤
PREN ≤ 48 respectively. For sour service, the maximum PREN for
25Cr Duplex filler metal shall be 45 as per NACE MR0175/ISO
15156.
7.1.4 GTAW process must be used for the root and cold passes if the wall
thickness is equal to or greater than 9.5 mm. Heat input for second
pass or cold pass should be approximately 75% to that of root pass to
prevent secondary austenite formation.
7.1.5 A change in metal transfer mode (e.g., dip/short circuit, globular,
spray) shall be considered an essential variable.
7.1.6 Repair of defective welds requires separate repair welding procedure
qualifications if duplex stainless steel was used for corrosion
resistance.
7.1.7 Ferrite content of the weld metal and HAZ shall be measured at root
pass, mid-thickness and cover pass. The ferrite range must be within
35 to 60% for the weld metal and 40 to 65% for HAZ as measured by
metallographic methods using a point count technique in accordance
with ASTM E562. Minimum ferrite content shall be 50% for services
that have potential for chloride stress cracking. The fabricator shall
establish a correlation between the percent ferrite as measured by
metallographic methods and the Ferrite Number (FN) as measured

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using AWS A4.2 for the weld metal. Ferrite measurements using both
methods shall be recorded on the PQR.
7.1.8 Corrosion testing to ASTM A923 Method C for Duplex & Super
Duplex Stainless Steels and ASTM A1084 Method C for Lean Duplex
Stainless Steel shall be performed.
7.1.9 Charpy impact testing shall be conducted on the weld metal and
HAZ at a test temperature of -20°C (-4 °F), or the minimum design
temperature, whichever is less. The minimum absorbed energy shall
be 34/27 J (25/20 ft-lb) for full size (10mm x 10 mm) specimens. All
of the ASME SEC IX supplementary essential variables for impact
tested applications shall apply.
7.1.10 The heat input shall be restricted to a minimum and maximum value.
If a single PQR is used, the WPS heat input shall be limited to plus or
minus 10% of the actual average PQR values. Otherwise, two PQR
coupons are required to establish both the minimum and maximum
allowable heat inputs. Portable Arc monitor (PAM) shall be used to
record the actual welding parameters & heat input while doing
procedure qualification test.
7.1.11 Maximum interpass temperature as recorded on the PQR shall be
considered an essential variable. In no case shall the interpass
temperature be greater than 150°C (300 °F), for 22Cr duplex stainless
steels and 100°C (212 °F), for 25Cr super duplex stainless steels. The
interpass temperature shall be checked or monitored with the use of
temperature indicating crayons suitable for these materials, pyrometers
or any other suitable methods.
7.1.12 Electrode & flux brand and type shall be considered an essential
variable. SAW Flux shall be a basic flux.
7.1.13 Hardness testing in accordance with Standard Drawing AB-036386
shall be conducted. Hardness shall not exceed 310 HV average, with
no single value above 320 HV for standard 22 Cr duplex stainless
steel grades. For all other grades, the limit shall be 340 HV average,
with no single value above 350 HV.
7.1.14 The requirements for purging in paragraph 6.5 shall be applicable,
unless specifically modified below.
7.2 Production Welding

7.2.1 The ferrite content of completed welds shall be checked in

accordance with AWS A4.2. It shall be within the range of 30 to 60%
ferrite using the appropriate Ferrite Number (FN) based on the
correlation established by the PQR measurements.
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7.2.2 The welding parameters shall be monitored in order to confirm

compliance with the minimum and maximum heat input restrictions.
7.2.3 For GTAW welding of duplex stainless steel, hydrogen free shielding
and purging gas (e.g., argon) shall be used to avoid possible cracking
and embrittlement of the weld. The purge shall achieve actual
oxygen levels inside or exiting the joint (via the vent) no greater than
0.05% prior to and during welding, as measured using an oxygen
analyzer. The actual oxygen levels achieved in production shall be
measured periodically (i.e., on a random basis for the number of
joints to be performed). Analyzers shall be used for all joints if
excessive internal oxidation is observed on any joints based on the
visual appearance of the oxide tint.
7.2.4 The interpass temperature shall be monitored to confirm compliance
with the maximum limit established by the PQR.
7.2.5 Hardness testing shall be conducted on a 20% random sampling of
all production welds. Both the weld metal and HAZ shall be tested.
Testing shall be conducted with portable hardness testers that
comply with ASTM A833. The hardness of the reference bar shall be
within ±10% of the maximum specified hardness. The maximum
hardness shall be 310 HV average, with no single value above 320
HV for standard 22 Cr duplex stainless steel grades. For all other
grades, the limit shall be 340 HV average, with no single value above
350 HV. Conversion charts in API TR 938 C shall be used for
determining acceptance of hardness measured and reported in other
scales.
8 Special Requirements for Titanium and its Alloys

Care to prevent contamination of the titanium by air must be exercised at all

stages of welding. Auxiliary gas or trailing gas shield shall be used to protect
the weld.
Note:
Molten titanium weld metal must be totally protected from contamination by air. Also, hot heat-
affected zones and root side of titanium welds must be shielded until temperatures drop below
750°F (400°C).
Similarly, hot titanium reacts with and is embrittled by most materials, including
organic and inorganic compounds and some metals. And in the case of
welding titanium to other refractory/reactive metals, detrimental alloy
compositions or compounds may form. Hence, the parts to be welded must be
meticulously cleaned of mill scale, oil and grease from machining operations,
dust, dirt, moisture, and other potential contaminants.

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The following requirements are in addition to all requirements previously

specified in this standard:

8.1 Qualification of welding procedures for titanium and its alloys shall
include the following supplementary essential variables and testing
requirements:

8.1.1 The base metal UNS number shall be considered an essential

variable.
8.1.2 The size of the filler wire used in welding of the test coupon is
considered an essential variable.
8.1.3 The trailing shield used for the qualification shall be the same as that
proposed to be used for the production.
8.1.4 Maximum interpass temperature as recorded on the PQR shall be
considered an essential variable. Interpass temperature shall be
checked with pyrometers or other suitable methods.
8.1.5 Filler wire brand and type shall be considered an essential variable.
8.1.6 A change in metal transfer mode (e.g., dip/short circuit, globular,
spray) shall be considered an essential variable.
8.1.7 If a single PQR is used, the WPS heat input shall be limited to plus or
minus 10% of the actual average PQR values. Otherwise, two PQR
coupons are required to establish both the minimum and maximum
allowable heat inputs
8.2 Production Welding

8.2.1 All titanium materials, including consumables, shall be handled and

stored in such a manner that they are protected from contact with
non-titanium materials, such as iron- or nickel containing materials
(storage racks can be lined with wood or plastic; wood blocks shall be
placed under titanium before it is set on a concrete surface; fork
protectors or wood shall be used between forks and titanium.
8.2.2 The welding area shall be kept clean and protected from dirt, smoke,
and other airborne contaminants from welding, cutting, and grinding
operations. The working area shall be protected from wind and drafts
that can interfere with inert gas shielding. The humidity in the welding
area shall be monitored and all equipment, fixtures, etc., shall be free
from moisture.
8.2.3 When tack welds are used, the same cleaning and shielding
requirements used for all titanium welds shall be employed, including
the use of trailing shielding and purging.
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 Document Responsibility: Welding Standards Committee SAES-W-016
Issue Date: 10 January 2022
Next Planned Update: 10 January 2027 Welding of Special Corrosion-resistant Materials

8.2.4 Before starting welding, the torch, trailing shield, and purging gas
hoses and devices shall be pre-purged to minimize potential
contamination at the start of welding. Welding equipment and the
GTA torch shall be equipped with upslope, downslope control for
current, pre-purge and post-purge controls for shielding gas.
8.2.5 Preheating, if used to remove moisture shall be carried out with
lamps, resistance heaters, or induction heating equipment; wiping
with a volatile solvent like acetone may also be used to dry material.
8.2.6 The welding parameters shall be monitored in order to confirm
compliance with the minimum and maximum heat input restrictions.
8.2.7 For GTA welding of Titanium and its alloys, only argon and helium or
a mixture of helium and argon is permitted for shielding, trailing and
purging. The purity of the gas shall be at least 99.995% and the dew
point of the gas shall be at least -60°F [-50°C].
8.2.8 The purge shall achieve actual oxygen levels inside or exiting the
joint (via the vent) no greater than 0.05% prior to and during welding,
as measured using an oxygen analyzer. Analyzers shall be used for
all joints if excessive internal oxidation is observed on any joints
based on the visual appearance of the oxide tint.
Note:
Light and dark straw colors indicate light contamination that is normally acceptable.
Dark blue indicates heavier contamination that may be acceptable depending on the
service conditions. Light blue, grey and white indicate such a high level of
contamination that they are regarded as unacceptable.
8.2.9 The interpass temperature shall be monitored to confirm compliance
with the maximum limit established by the PQR.
8.2.10 Hardness testing shall be conducted on a 20% random sampling of
all production welds. Both the weld metal and HAZ shall be tested.
Testing shall be conducted with portable hardness testers that
comply with ASTM A833. The hardness of the reference bar shall be
within ±10% of the maximum specified hardness. The maximum
hardness shall be BHN 285 for non-sour services. The maximum
hardness shall be BHN 270 for sour service unless NACE
MR0175/ISO 15156 specifies a lower value, as determined by using
the hardness conversion between HRC and BHN in accordance with
ASTM E140.
8.2.11 Repairs are not permitted, weld shall be cut out and rewelded in the
case of any defects.

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 Document Responsibility: Welding Standards Committee SAES-W-016
Issue Date: 10 January 2022
Next Planned Update: 10 January 2027 Welding of Special Corrosion-resistant Materials

Revision Summary
10 January 2022 Major revision. Incorporate additional requirements as part of the alignment with
IOGP S-705.
20 February 2019 Major revision. Clarify the welding purging requirements for stainless steel
materials to prevent the recurrence of MIC filature in SA capital projects in line
with SAER-8166. Clarity the RT and UT procedure and acceptance criteria
similar to the mother welding standards SAES-W-011 and in line with ASME
requirements. Maintain the welding standards up to date aligned with the
international requirements/ practices and easily interpreted.
1 January 2018 Editorial revision to modify and/or delete paragraph 6.1 (4).
10 November 2014 Major revision to revising requirements for duplex stainless steel welding and
added requirements for qualification. Added requirements for Titanium welding
qualifications and production welding.

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 Document Responsibility: Welding Standards Committee SAES-W-016
Issue Date: 10 January 2022
Next Planned Update: 10 January 2027 Welding of Special Corrosion-resistant Materials

Table 1 - Filler Metal and Electrode Selection (1)

Base Metal (4) GTAW Filler Metal SMAW Electrode
6%Mo super-austenitic stainless steel ERNiCrMo-3 (2) ENiCrMo-3 (2)
Alloy 400 ERNiCu-7 ENiCu-7
Alloy 20 ERNiCrMo-3 (2) ENiCrMo-3 (2)
Alloy C22/C276 ERNiCrMo-4 ENiCrMo-4
Alloy B2 ERNiMo-1 ENiMo-1
Alloy 600 ERNiCr-3 (3) ENiCrFe-3 (3)
Titanium and its alloys See note (6) Not Applicable
Notes:
1) Contact CSD for base metals not listed or for approval of alternative consumables. Ni-Fe-Cr alloys shall
not be welded with ENiCu-7 or ERNiCu-7 type consumables, to avoid hot cracking (liquid metal
embrittlement). For welding austenitic stainless steels in corrosive services, either low-carbon (C< 0.03%)
or stabilized filler materials shall be used. Weld metal containing Nb should not be avoided for service with
temperatures below -105°C (-157 °F).
2) Acceptable substitutes are ERNiCrMo-4 and ENiCrMo-4, respectively, for GTAW and SMAW.
3) Acceptable substitutes are ERNiCrMo-3 and ENiCrMo-3, respectively, for GTAW and SMAW.
4) (See SAES-L-132)
5) Common trade names are:
ERNiCrMo-3 (GTAW) Inconel 625
ENiCrMo-3 (SMAW) Inconel 112
ERNiCr-3 (GTAW) Inconel 82
ENiCrFe-3 (SMAW) Inconel 182
ERNiCu-7 (GTAW) Monel 60
ENiCu-7 (SMAW) Monel 190
6) Selection of filler metals for Titanium and its alloys shall be in accordance with AWS G2.4/G2.4M:2007.
The filler materials shall conform to the requirements of ASME SEC IIC, SFA 5.16.

Table 2 - Backing Gas Purge Times for Stainless Steel and Nickel alloy Pipe
Nominal Pipe Size (NPS) Purge Time (minimum)
2 inch (50.8 mm) 0.5 minutes
4 inch (101.6 mm) 2 minutes
6 inch (152.4 mm) 4 minutes
8 inch (203.2 mm) 7 minutes
10 inch (254.0 mm) 10 minutes
12 inch (304.8 mm) 15 minutes
16 inch (406.4 mm) 25 minutes
Assumes use of argon gas at a flow rate of 20 CFH (9 lpm).
Listed times are for each 300 mm of pipe length to be purged
(multiply by actual length). Use the values for 300 mm for any
shorter length.
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