Each set of norms and rules specifies defined criteria for performance of tests in the course of welding procedure qualification. Acting as a welding inspector you may need to participate in this estimation as well as in the performance of tests themselves. Probably the most important task of the welding inspector during performance of qualification consists in close observation over performance of Continue reading →
Tensile test (Part 4).
After the specimen for tensile test was measured and marked, it needs to be fastened safely in gripper of mobile and motionless heads of machine for tensile testing.
After setting the specimen in gripper, the increasing with constant speed tensile stress is applied to the specimen. If increasing speed of tensile stress is not constant, the test results can be unstable. Before the stress is applied to the Continue reading →
Inclusions in the weld seams (Part 2).
The slag density is significantly less than the metal density, in the radiographic picture slag inclusions look like relatively dark irregular-shaped sections. However, several coated welding electrodes form slags approximately of the same density as the metal density. Expectedly, in case of slag inclusions which are formed as a result of use of such electrodes it is highly difficult to detect them by means of Continue reading →
Incomplete fusion of the root of the welded seam.
Incomplete fusion of the root of the welded seam is a result of applying of low current and high welding speed.
This is considered to be a permissible defect.
The repair of the incomplete fusion is regulated by standard documentation for welding.
Methods of technological strength evaluation.
One of the basic trial tasks, conducted during technological weldability of materials determination, is evaluation of its technological strength under conditions of any welding method, as with strength increasing the possibility of high-quality welded connection realization increases. Term “technological strength” was introduced by Prochorov N.N. in 1950. This term underlines, that we are speaking about the Continue reading →