Flaw Implant Techniques

FlawTech has the capability to use several methods to implant flaws in a variety of configurations for nondestructive testing applications. In the following data we have described a few of these methods so you may gain a better understanding of our flaw manufacturing
possibilities.

In-Situ Implant— This technique has been the corner stone of flaw manufacturing for many years and usually involves thermal or mechanical fatigue cracks. The important characteristic is that the flaw occurs in virgin base material (i.e. HAZ) so that UT energy can impinge directly on the crack face without traveling through weld metal. The process allows for precise mechanical dimensions of the flaw face to be taken prior to implant. As shown below, this technique
allows the crack to be "branched" and this is the best way to replicate the UT signal from IGSCC.

Coupon Implant— This process has the advantage of producing the flaw in a small coupon in the laboratory and then implanting the coupon into the mockup. The disadvantage is that precise mechanical dimensions are usually not possible and the coupon is surrounded by
weld metal which may introduce additional UT reflectors.

Controlled Flaw— This is a unique proprietary process developed by FlawTech to progressively extend a "crack-like" indication in any area in carbon steel and within the weld groove in stainless steel or Inconel. This process is often used in the production of "Dissimilar Metal"
specimens.

Weld-Solidification Crack— This technique is occasionally used when a crack is desired within the weld groove. The weld is "contaminated" by changing weld chemistry in a designated area to produce a crack. Disadvantages include uncertainty about the orientation and extent of cracking and crack size.

HIP (Hot Isostatic Process)— This technique is used to tighten the tips of manufactured flaws. HIP is also used to tighten EDM Notches in an effort to make them look like cracks. Disadvantages include uncertainty as to how the grain structure of the base metal is effected
and the characteristics of the response to an EDM notch as well as
adding time and cost to the manufacturing process.

In addition to the aforementioned, FlawTech uses a variety of other basic techniques for implanting slag, porosity, lack of fusion, under bead cracking, etc. FlawTech offers 3 levels of tolerance; Standard +/- 0.150", Advanced +/- 0.080" and Critical +/- 0.040", contact
FlawTech for more details.