Weld penetration testing instructions

The pre-heat does not prevent the formation of crack —susceptible microstructures; it just reduces one of the factors, hydrogen, so that cracking does not occur. In addition, this may also produce false indications severely hindering the ability to do a proper inspection. Equipment Inspection. The weld pool is submerged by flux fed from a hopper. Shielding gases are normally a mixture of argon, carbon dioxide and possibly oxygen or helium. This also means that personal protection requirements are less. The penetration test is a widely used test method that is used in almost all industrial sectors.

If you want a Miller or Hobart you will have to seek out your local welding supply company. The term "X-ray quality," widely used to indicate high quality in welds, arises from this inspection method. Computerization has made it possible to overcome many of the shortcomings of radiographic imaging by linking the fluorescent screen with a video camera. Did you make this project? During fabrication, visual examination of a weld bead and the end crater may reveal problems such as cracks, inadequate penetration, and gas or slag inclusions. When you power, wire speed and travel speed are all in line you welding will make a sound similar to cooking bacon, a nice steady sizzle. Ultrasonic Inspection UT Ultrasonic inspection is a method of detecting discontinuities by directing a high-frequency sound beam through the base plate and weld on a predictable path.

The ultrasonic unit contains a crystal of quartz or other piezoelectric material encapsulated in a transducer or probe. A magnetic powder dusted onto the surface will cling to the leakage area more tenaciously than elsewhere, forming an indication of the discontinuity. For example, both radiography and ultrasound have distinct orientation factors that may guide the choice of which process to use for a particular job. I have included two videos that will help explain a little better.