《Liccoln WPHB - Section 03 (Variables in Welding Fabrication)》.pdf

Section 3 VARIABLES IN WELDING FABRICATION SECTION 3.1 WELDMENT DISTORTION Page The Reasons for Distortion 3.1-1 How Properties of Metals Affect Distortion . . . . . . . . . . . . . . . . . . . . . . . .. 3.1-3 Shrinkage Control .. . . . . . . . . . . . . . . . . .. 3.1-4 Equations for Calculating Shrinkage 3.1-7 Examples of Distortion Control 3.1-9 Shop Techniques for Distortion Control .. 3.1-17 Check List for Minimizing Distortion 3.1-19 SECTION 3.2 ARC BLOW Magnetic Arc Blow 3.2-1 Thermal Arc Blow . . . . . . . . . . . . . . . . . . . .. 3.2-3 Arc Blow With Multiple Arcs . . . . . . . . . . .. 3.2-3 How to Reduce Arc Blow 3.2-4 The Effects of Fixturing on Arc Blow . . . .. 3.2-5 SECTION 3.3 PREHEATING AND STRESS RELIEVING Preheating - When and Why 3.3-1 The Amount of Preheat Required 3.3-1 Methods of Preheating. . . . . . . . . . . . . . .. 3.3-3 Interpass Temperatures. . . . . . . . . . . . . . . .. 3.3-4 Preheats for Quenched and Tempered Steels 3.3-4 Pointers on Preheat 3.3-5 Stress Relief 3.3-6 3.1-1 Weldment Distortion There are several problems or variables common bar of steel shown