🔍 Key Concepts

• Effect of heat on metal during long welds • How welding sequence impacts distortion and residual stress • Difference between weld strength vs. shape/control of the structure

💭 Think About

• When you run a long continuous weld, what happens to the plate or structure as it heats up and then cools? Think about bending, warping, or pulling. • Do back-step and skip welding spread heat out or concentrate it in one area? How would that affect the final shape of the welded pieces? • Is the main goal of these techniques to change the metal’s mechanical strength, or to control what happens to the structure while it is being welded?

✅ Before You Answer

• Recall that uneven heating and cooling can cause warping or bowing of plates. • Ask yourself whether these techniques are mainly about strength or about controlling shape/fit-up during welding. • Eliminate any option that clearly contradicts the idea of controlling or reducing unwanted effects from welding heat.