Книги

Technologies of Underwater Wet Welding and Cutting

CONTENTS
Introduction ... 5
Chapter I. Underwater Welding ... 9
Features of arcing in underwater welding ... 9
Energy characteristics of the arc ... 15
Metal transfer in underwater welding ... 17
Metallurgical features of underwater welding process ... 24
Electrode materials for underwater welding ... 29
General principles of electrode material development ... 29
Coated electrodes ... 31
Self-shielded flux-cored wire ... 34
Technologies of consumable-electrode underwater welding ... 49
Types of welded joints ... 49
Edge preparation and fit-up for welding ... 52
Butt welding ... 53
Fillet welding ... 57
Influence of welding process parameters and water salinity on weld shape ... 58
Selection of welding mode ... 62
Influence of welding circuit length on weld metal formation ... 63
Technological solutions for welding operations performance under the water ... 66
Main requirements ensuring welding quality and higher labour efficiency ... 67
Typical defects of welded joints, causes for their formation and methods to eliminate them ... 68
Equipment for consumable electrode underwater arc welding ... 80
General requirements ... 80
Equipment for coated-electrode welding ... 81
Equipment for mechanized and automated underwater welding ... 82
Technologies of welding and repair of underwater metal structures ... 92
General ... 92
Repair of water pipelines ... 93
Repair of underwater passages of gas and oil pipelines across water obstacles ... 95
Ship salvaging and repair ... 98
Repair of waterfront facilities ... 107
Repair of off-shore platforms ... 107
Assembly of large-sized metal structures ... 108
Chapter II. Thermal Underwater Cutting ... 115
General ... 115
Oxy-arc cutting by tubular metal electrode ... 116
Coated-electrode underwater arc cutting ... 124
Mechanized flux-cored wire underwater cutting ... 127
Underwater cutting with exothermal electrodes ... 133
Plasma cutting under the water ... 139
Oxy-gas underwater cutting ... 142
Explosion cutting ... 145
Reference ... 147