AS/NZS 2312.2:2014

AS/NZS 2312.2:2014 GUIDE TO THE PROTECTION OF STRUCTURAL STEEL AGAINST ATMOSPHERIC CORROSION BY THE USE OF PROTECTIVE...

PREFACE

CONTENTS

1 SCOPE

2 REFERENCED DOCUMENTS

3 DEFINITIONS

3.1 Atmospheric corrosion

3.2 Elevated temperatures

3.3 Exceptional exposure

3.4 Hot dip galvanized coating

3.5 Hot dip galvanizing

3.6 Life to first maintenance

4 MATERIALS-IRON AND STEEL SUBTRATES

5 ZINC COATINGS

5.1 Types of coating

5.1.1 General

5.1.2 Hot dip galvanized coatings (applied after fabrication to AS/NZS 4680 and AS 1214)

5.1.3 Hot dip galvanized coatings (applied onto continuous sheet to AS 1397)

5.1.4 Hot dip galvanized coatings (applied onto continuously cold-formed shapes to AS/NZS 4791 and AS/NZS 4792)

5.1.5 Mechanically plated coatings (to AS 5056)

5.1.6 Electrodeposited coatings (to AS 1789, AS 1897 or AS 4750)

5.2 Selection of hot dip galvanized coating

6 CORROSION IN THE ATMOSPHERE

6.1 General

6.2 Atmospheric corrosivity in Australia and New Zealand

6.3 Life to first maintenance of coatings

6.3.1 General

6.3.2 Criteria for assessing when to repair or regalvanize

6.4 Accelerated test methods applied to zinc coatings

7 GENERAL DESIGN REQUIREMENTS

7.1 General principles of design to avoid corrosion

7.2 Tubes and hollow sections

7.2.1 General

7.2.2 Corrosion protection of internal and external surfaces

7.3 Connections

7.3.1 Fastenings to be used with coatings

7.3.2 Welding considerations related to coatings

7.3.3 Brazing or soldering

7.4 Maintenance of coatings

7.5 Duplex systems

7.5.1 General

7.5.2 Painting for decorative, identifying colour or enhanced service life

7.5.3 Preparation for painting

7.5.4 Painting for unwashed surfaces

7.5.5 Painting for exposure to soil and/or prolonged dampness

7.5.6 Painting for specific industrial chemical or solvent exposure

7.5.7 Painting for lintels and shelf angles in masonry construction

7.5.8 Maintenance of duplex coatings

7.6 Design for storage and transport

8 DESIGN FOR HOT DIP GALVANIZING TO AS/NZS 4680

8.1 General

8.2 Surface preparation

8.3 Procedures related to design considerations

8.4 Design features

8.5 Tolerances

8.5.1 General

8.5.2 Dimensional tolerances on mating threads

9 EFFECT OF ARTICLE CONDITION ON QUALITY OF HOT DIP GALVANIZING TO AS/NZS 4680

9.1 Material composition

9.2 Mechanical properties of processed steel

9.3 Castings

9.4 Surface condition

9.5 Influence of steel surface roughness on the coating thickness

9.6 Influence of thermal cutting processes

9.7 Effect of internal stresses in the base steel

9.7.1 General

9.7.2 Distortion cracking

9.7.3 Hydrogen embrittlement

9.7.4 Cold-work (strain-age) embrittlement

9.7.5 Liquid metal assisted cracking (LMAC) or liquid metal embrittlement (LME)

9.8 Large objects or thick steels

9.9 Hot dip galvanizing practice

APPENDIX A - PREFERRED DESIGNS OF ARTICLES FOR HOT DIP GALVANIZING TO AS/NZS 4680

APPENDIX B - CORROSION IN DIFFERENT ENVIRONMENTS

B1 EXPOSURE TO SOILS

B2 EXPOSURE TO WATER

B3 ABRASION

B4 EXPOSURE TO CHEMICALS

B5 ELEVATED TEMPERATURES

B6 EMBEDDED IN CONCRETE

B7 CONTACT WITH WOOD

B8 BIMETALLIC CONTACT

APPENDIX C - INSPECTION OF HOT DIP GALVANIZED COATINGS

BIBLIOGRAPHY