Steam boiler explosions in the 1800s claimed many lives. In response to these accidents, ASME (The American Society of Mechanical Engineers) created a system of voluntary welding codes and specifications to ensure pressure vessel weld integrity.
In production, non-destructive inspection techniques such as visual, ultrasonic, X-Ray, and magnetic particle testing can only measure weld dimensions and check for defects such as cracks or lack of fusion. Non-destructive inspection cannot measure the weld’s mechanical properties, heat-affected zone, or base metal. This requires destructive testing of each part the which is impractical as the part is destroyed. However, if a qualified welder follows a weld procedure qualified by the destructive testing of a representative test part, you can reasonably expect acceptable mechanical properties.
In this episode, we use a Xiris Automation Inc. weld video system to show the process of welding a test plate in preparation for destructive testing. We are welding a high-strength, low alloy quenched and tempered steel plate with a hot wire gas tungsten arc using hot wire.
In future episodes, we will take you to the lab to witness how we prepare specimens and test strength, hardness, and toughness.