Welding Inspection & Metallurgy API ICP Self Study Notes

Another approach to measuring susceptibility to weld cracking is to apply an
external load during welding or subsequent to welding. The loading is
intended to duplicate or magnify stresses from restraint of a rigid weld joint.
The tests provide an ability to control the stress and strain applied to the weld
joint and, therefore, provide a relative index of the susceptibility to weld
cracking.
Test methods that use external loading include;
■ the implant test,
■ tension restraint cracking (TRC) test, and
■ varestraint test.
There is also a very specialized test called the Gleeble test that also applies a
load to the specimen during heating or melting of the metal. It is beyond to the
scope of this document to describe each test in detail; however, a general
overview of different types of tests and what types of defects they can detect
are given in Table 12.