Why is it considered good practice to normalize a part after welding?

• A. To relieve internal stresses developed with the base metal
• B. To increase hardness
• C. To improve corrosion resistance
• D. To reduce weight

Answer: (A)

Normalizing a welded part focuses on relieving residual stresses that form when metal is heated and then cooled during welding. The weld area and surrounding base metal experience different heating and cooling rates, which creates internal stress that can lead to distortion or cracking if left in place. By heating the part above its critical temperature to form a uniform austenitic structure and then letting it cool in air, the grain structure becomes finer and the stresses are reduced. This improves toughness and dimensional stability, making the part less prone to distortion or crack propagation in service. It isn’t primarily about increasing hardness, boosting corrosion resistance, or reducing weight, so those effects aren’t the main reason for normalization.