Page 5 - SSAB Welding Handbook Edition 2

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Welding handbook 1.0 Index

1.0 Index

2.0 Introduction 5.0 The properties of the heat-affected zone
2.1 The Hardox and Strenx grades 10 5.1 The different parts of the HAZ 31
The Hardox grades 10 The coarse grained zone 32
The Strenx grades 11 The fine grained zone 33
The partially transformed zone
©SSAB 33
The annealed zone 33
3.0 The thermal cycle of a welding performance 5.2 The width of the HAZ 33
3.1 The heat input 13 The hardness values in joints of Hardox and Strenx 33
3.2 The heat-affected zone 13 Hardness properties in the HAZ for
3.3 Description of the thermal cycle 14 Strenx 700-960 and Hardox HiTuf 34
3.4 The calculation of the t value 15 The effect of heat input with regard to the
8/5
The t value during two-dimensional heat flow 16 hardness values in the HAZ 34
8/5
The t value during three-dimensional heat flow 17 Effects of the chemical composition in
8/5
the steel 35
Welding with a single-pass sequence
4.0 Hydrogen cracks compared to a multi-pass sequence 35
5.3 Recommended levels of heat input and t values 35
4.1 Description of crack appearance 19 5.4 Measures for additional improvements 8/5
4.2 The influence of alloy elements in the steel 20 of the mechanical properties in the HAZ 38
4.3 The influence of alloy elements in unalloyed and
low-alloyed consumables 21
4.4 Hydrogen content in the joint 21 6.0 The choice of consumables
Hydrogen levels in unalloyed and low-alloyed
consumables 21 6.1 Unalloyed and low-alloyed consumables 39
Welding environment issues 22 6.2 The static strengths of the consumables 39
Hydrogen presence in the steel and its primer 22 6.3 The toughness values in the weld metal 40
4.5 Preheat temperatures during welding of the 6.4 The maximum hydrogen content in the consumables 40
Hardox and Strenx grades 22 6.5 Handling of consumables 41
Preheat levels for the Hardox and Strenx grades 23 6.6 Preheat requirements due to the properties
Preheat requirements for low-alloyed, high of the consumable 41
strength consumables 25 6.7 Stainless austenitic consumables 42
4.6 Stainless steel consumables 25
4.7 The preheat performance 26
4.8 Interpass temperatures 26 7.0 Aspects regarding static strength in joints
4.9 Post-weld heat treatment 27 7.1 Issues to consider during the tensile test 44
4.10 Practical recommendations for removal of
hydrogen from of the joint 27
4.11 Tensile stresses in the HAZ and the weld metal 27 8.0 Fatigue in welded joints
4.12 Measures that reduce the residual stresses in 8.1 Introduction 47
joints during welding 29 8.2 Fatigue load 47
4.13 Recommendations for consumables for welding 8.3 Fatigue strength in welded joints 48
of the Hardox grades 29 8.4 Weld quality 50
4.14 A suitable measure for welding a multi-pass joint 8.5 Nominal stress method 50
in the Strenx grades 29 8.6 Improvement methods 52
4.15 Critical size and acceptance levels of hydrogen cracks 30 8.7 TIG-dressing 53
4.16 Summary of measures to minimize the risk for 8.8 Burr grinding 54
hydrogen cracks in joints 30 8.9 Hammer peening 54
8.10 High frequency mechanical impact, HFMI 54
8.11 Post-weld heat treatment (PWHT) 54
8.12 Other methods 54

This handbook contains general suggestions and information without any expressed or implied warranty of any kind. SSAB hereby expressly disclaims
all liability of any kind, including any damages, in connection with the use of the information and for their suitability for individual applications. 5
It is the responsibility of the user of this brochure to adapt the recommendations contained therein to the requirements of individual applications.