Iso 12944 - 2018

ISO 12944 - 2018

Reason for coating failure 1992

Reason for Coating Failure 2000

What is ISO 12944

Comprehensive “instructions” providing guidance for engineers, consultants, contractors and coatings suppliers when dealing with the corrosion protection of steel structures by protective paint systems.

“Instructions” divided into 9 separate parts

Defines “Durability” of coating systems Defines “Corrosivity Categories” of environments Provides guidance in coating system specifications

Local Standards that Adopt ISO 12944

Surat Edaran Menteri Pekerjaan Umum dan Perumahan Rakyat, Nomer : 26/SE/M/2015, tanggal 23 April 2015, tentang Pedoman Perlindungan Komponen Jembatan dengan cara Pengecatan. Standar Nasional Indonesia (SNI) ISO 12922-5:2012, tentang Cat dan Pernis – Perlindungan dari Korosi pada Struktur Baja dengan Sistem Pengecatan bagian 5 : Sistem Pengecatan Pelindung

Part 1 – General Introduction

Durability : The level of coating failure prior to first major maintenance painting. Agreement between interested parties (based on ISO 4628-1 & ISO 4628-5), e.g. Ri2 (0.5%) or Ri3 (1%) Not a guarantee time ! Expressed in terms of 3 ranges  4 ranges (2018)

Part 1 – General Introduction

 Durability Range - current  low (L):

2 to 5 Years

 medium (M):

5 to 15 Years

 high (H):

more than 15 Years

 Durability Range - proposed  low (L):

up to 7 Years

 medium (M):

7 to 15 Years

 high (H):

15 to 25 Years

 very high (VH):

more than 25 Years

Part 1 – General Introduction

 Classification of environments

 12944:2007 C1 to C5M/I  12944:2018 C1 to Cx  12944:2007 Im1 to Im3  12944:2018 Im1 to Im4

Part 1 – General Introduction Integration of ISO 20340 as Part 9

Part 2 – Classification of Environments

Atmospheric -: defined from weight loss of metallic (low carbon steel and zinc) specimens over a defined period of 1 year (not more and not less).

There are obvious differences in this approach because of change of climate on a yearly basis, but this certainly helps quantify the corrosivity of an environment.

Water & Soil (Immersed / Buried)

Part 2 – Classification of Environments

catergory

corrosivity

Examples (outdoor)

C2

Low

Temperate zone, atmospheric environment with low pollution SO2: <5 μg/m3 eg rural areas Dry or cold zone with short time of wetness

C3

Medium

Temperate zone, atmospheric environment with medium pollution (SO2: 5 μg/m3 to 30 μg/m3) or some effect of chlorides, e.g. urban areas, coastal areas with low deposition of chlorides Subtropical and tropical zone, atmosphere with low pollution

C4

High

Temperate zone, atmospheric environment with high pollution (SO2: 30 μg/m3 to 90 μg/m3) or substantial effect of chlorides, e.g. polluted urban areas, industrial areas, coastal areas without spray of salt water or, exposure to strong effect of de-icing salts Subtropical and tropical zone, atmosphere with medium pollution

C5

Very high

Temperate and subtropical zone, atmospheric environment with very high pollution (SO2: 90 μg/m3 to 250 μg/m3) and/or significant effect of chlorides, e.g. industrial areas, coastal areas, sheltered positions on coastline

Cx

extreme

Subtropical and tropical zone (very high time of wetness), atmospheric environment with very high SO2 pollution (higher than 250 μg/m3) including accompanying and production factors and/or strong effect of chlorides, e.g. extreme industrial areas, coastal and offshore areas, occasional contact with salt spray

Part 2 – Classification of Environments

New Categories for Underwater / Immersed Structures Category

Environment

Examples of environments and structures

Im1 Im2 Im3 Im4

Fresh water Sea or brackish water Soil Sea or brackish water

River installations, hydro-electric power plants Immersed structures without cathodic protection Buried tanks, steel piles, steel pipes Immersed structures with cathodic protection

Immersion category IM4 for offshore use only

Part 2 – Classification of Environments

Corrosion Categories:  No division into C5M and C5I anymore: corrosion category C5 only  Corrosion category Cx (extreme corrosion) is added. Remark: Cx = Offshore covered in Part 9 only, no other “extreme environments“ in ISO 12944.  New examples for table 1 (corrosion categories)

Part 3 – Design Consideration Basic design criteria to avoid premature corrosion / coating degradation. Outside the scope of protective coatings manufacturers.

This can only really be fully implemented at the new Construction stage or by major modification at a later date. Coatings are often expected to alleviate, or help alleviate, corrosion problems due to design errors. ◦ E.g. thick film coatings / edge retentive

Part 3 – Design Consideration

Part 4 – Type surface and Surface preparation Describes types of surfaces to be coated ◦ Mill scale steel, thermal sprayed, hot dip galvanized, zinc-electroplated etc

Describes surface preparation methods ◦ Water cleaning, steam cleaning, solvent cleaning ◦ Hand tool / power tool cleaning ◦ Blast cleaning (dry & wet) ◦ Types e.g. centrifugal, compressed air, vacuum etc

◦ Sweep blasting / spot blasting ◦ Water blast cleaning (HP, UHP)

◦ Grades / standards ISO (Sa, St etc)

Part 5 – Protective Paint Systems ISO 12944 can be seen as a tool for providing the customer with a solution to their anticipated structural steel corrosion problems. This means supplying an adequate protective coating system that will meet both the durability and corrosive category requirements. 1. Use Part 2 to select the corrosive category for where the steel structure will be located.

2. Decide on the design life (durability) requirements of the protective coating system, (Low/Medium/High). 3. Use Part 5 to choose the most effective coating system to meet these needs.

Part 5 – Protective Paint Systems

Part 5 – Protective Paint Systems Selecting coating specs via ISO 12944 part 5 provides the customer with: Confidence that the corrosion protection will meet the demands of the environment and design life  An objective approach to coating selection  A simplified matrix of proven coating systems to chose from  A meaningful coating design life  A globally accepted standard

Part 5 – Protective Paint Systems

Amendments  Obsolete binder were eliminated.  Remark regarding “alternative topcoats” was added (Polysiloxanes, Polyaspartics, Fluor polymers)  Remark regarding “innovative systems” was added.  Passage regarding “well proven” systems was added.

Part 5 – Protective Paint Systems

Amendments  Annexes A and B are normative now rather than informative. The minimum requirements are clearly defined and binding.  Systems for “very high durability“ added to tables.  Revision of the tables and number of systems reduced – new numbering protocol.

Part 5 – Protective Paint Systems Annex B (normative) – Minimum number of coats, minimum requirement for the overall dry film thickness for C2 to C5 on blasted steel

Note: The DFTs were partly reduced.

Part 5 – Protective Paint Systems Annex B (normative) – Minimum number of coats, minimum requirements for the overall dry film thickness for C2 to C5 on galvanized steel

Part 5 – Protective Paint Systems

Annex B (normative) – Minimum number of coats, minimum requirements for the overall dry film thickness for C2 to C5 on thermally sprayed steel

Part 5 – Protective Paint Systems Annex C (informative) – Protective Paint Systems for Corrosivity Category C5 for Low-Alloy Carbon Steel

Example tables available for all the other corrosivity categories

Part 5 – Protective Paint Systems Selection of non-standard coating systems: 1. Innovative Systems „New innovative coating technologies when available may provide equivalent corrosion protection, at lower NDFT and/or reduced MNOC compared to the current coating technologies covered in this standard.“ → These systems can be used, when tested according ISO 12944 – part 6 and based on track records.

2. Well-proven Systems „The same applies to proven systems that have been performing well over a long field experience period despite not fulfilling the requirements concerning minimum number of coats and minimum dry film thickness.“ → These systems can be used based on long term track records.

Part 6 – Laboratory Performance Test Methods Specifies lab based performance tests for the assessment of coating systems ◦ Corrosivity environments considered ◦ Durability range considered

Basic PC industry tests utilized / short term duration ◦ ◦ ◦ ◦

Neutral salt spray (ISO 7253) Condensation (ISO 6270) Water immersion / Chemical resistance (ISO 2812-1, 2) C5 dealt with via new ISO 20340

Part 6 – Laboratory Performance Test Methods Corrosion Tests Testing method for corrosion category C4 and C5: Proposal: Cyclic testing according ISO 20340 would be used for

•

C4 very high - 10 cycles (alternatively salt spray and continuous condensation)

•

C5 high - 10 cycles (alternatively salt spray and continuous condensation)

•

C5 very high - 16 cycles

Remark:

Cx offshore = 25 cycles

Part 6 – Laboratory Performance Test Methods Corrosion Tests  Corrosion creep and delamination based on average of 9 measurements.  Scribe width = 2 mm  Scribe acceptance 1mm for salt spray and 3mm for CCT regardless of primer used  No test requirements for Cx added covered in part 9

Part 7 - Execution of work Deals with ◦ ◦ ◦ ◦ ◦

Substrate Condition H&S Supply / Storage / Application Conditions / Methods Supervision / Measurement (dft) Reference Areas ◦ Establish minimum acceptable standard for work

◦ Allows assessment at any time ◦ Can be used as part of guarantee (if agreed)

Part 8 – Development of Specifications for New Work and Maintenance Provides guidance (engineers) for the development of coating specifications Takes into account information from parts 1 – 7 “Flow Charts” for project planning

Checklists / examples

Part 9 – Protective Paint Systems for Offshore

Corrosion Categories – Amendments to current ISO 20340  Corrosion Category C5M will become Cx Offshore  Immersion Category IM2 will become IM4

Part 9 – Protective Paint Systems for Offshore Acceptability criteria for the laboratory tests  Uniform requirements regarding corrosion creep for zinc primer and non zinc primers  Uniform minimum requirements for pull-off adhesion

 Min. 5 MPa prior testing  Min. 2,5 MPa after ageing without adhesive break

Part 9 – Coating Systems for Offshore Maximum Corrosion Creep The maximum values for corrosion creep will still be heavily discussed. According to the current status the following values are intended:  Max. 8 mm for tidal zone / splash zone (cyclic testing)  Max. 3 mm for all atmospheric conditions (cyclic testing)

 Max. 6 mm for immersed areas (immersion testing) .

Question and Answer