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9.1 What is elastic deformation? 9.2 Describe shrinkage on steel - NSC Mechanical Technology Welding and Metalwork - Question 9 - 2022 - Paper 1
Question 9
9.1 What is elastic deformation? 9.2 Describe shrinkage on steel. 9.3 Study FIGURES 9.1 and 9.2 below and identify EACH distortion. 9.3.1 9.3.2 9.4 What effect ... show full transcript
Worked Solution & Example Answer:9.1 What is elastic deformation? 9.2 Describe shrinkage on steel - NSC Mechanical Technology Welding and Metalwork - Question 9 - 2022 - Paper 1
Step 1
What is elastic deformation?
Answer
Elastic deformation refers to the ability of a joint or material to return to its original position or dimensions after the stresses have been relieved. This means that when a force is applied to the material, it undergoes a temporary deformation, but once the force is removed, it resumes its initial shape.
Step 2
Describe shrinkage on steel.
Answer
Shrinkage on steel is a form of plastic deformation that occurs as a result of contraction during cooling. When steel is heated during processes like welding, it expands. As it cools, the metal contracts, leading to shrinkage that can cause distortions in the material.
Step 3
Identify EACH distortion.
Answer
9.3.1 Transverse shrinkage: This refers to the shrinkage that occurs across the width of the weld, which can result in the warping of the material.
9.3.2 Longitudinal shrinkage: This is the shrinkage that occurs along the length of the weld, potentially causing elongation or distortion in that direction.
Step 4
What effect do the following factors have on shrinkage of steel during arc welding?
Answer
9.4.1 Electrode size: A larger electrode size requires a higher current and causes higher welding temperatures, which can lead to more deformation and shrinkage. Conversely, a smaller electrode size requires lower current and results in lower welding temperatures, causing less deformation/shrinkage.
9.4.2 Welding speed: Increased welding speed tends to decrease localized heat which helps control distortion, while decreased welding speed leads to increased localized heat causing greater distortion.
Step 5
Explain the disadvantage of using jigs, fixtures and clamps when welding.
Answer
Using jigs, fixtures, and clamps can increase internal stresses in the welded joint because the movement of the metal is restricted. This restriction can lead to complications such as warping or cracking in the final structure.
Step 6