Weld testing

From tests with Level-2-inspectors [2, 3] we learn that 10 % of the errors in weld testing are caused hy too fast probe movements (indications are missed or overlooked), 34 % by too strong coupling variations (underestimation of indications) or coupling failures and 56 % by incomplete scanning (untested areas). 

ISONIC - the intelligent ultrasonic weld test system... 

Facts that will revolutionize manual ultrasonic weld testing... 

Side drilled holes are widely used as reference reflectors, especially when angle beam probes are used (e.g. for weld testing). However, the distance law of side drilled holes is different to that of a flat bottomed hole. In the literature [2] a conversion formula is given which allows to convert the diameter of a side drilled hole into the diameter of a flat bottomed hole and vice versa, valid in the far field only, and for diameters greater than 1.5 times the wave length. In practical application this formula can be used down to approximately one nearfield length, without making big mistakes. Fig. 2 shows curves recorded from real flat bottomed holes, and the uncorrected and corrected DGS curves. 

Nondestmctive evaluation, also termed nondestmctive testing or nondestmctive inspection, is extensively used in weld testing (14). Nondestmctive tests do no impair the serviceabiUty of the material or component under stress. The most widely used tests for evaluation of welds are Hquid penetrant, magnetic particle, ultrasonics, and radiography. Acoustic-emission tests are increasingly used. Nondestmctive tests detect and characterize, in terms of size, shape, and location, the various types of weld discontinuities that can occur. 

In view of the widespread use of welded joints in equipment and structures exposed to corrosion, it is necessary to know whether such welded joints will demonstrate satisfactory resistance to attack. It is not necessary to include welded specimens of all materials in a preliminary study to discover which of them have satisfactory resistance to a particular environment. Weld tests can be postponed until the preliminary selection has been made, or, alternatively, those materials expected in advance to be most likely to be resistant can be exposed in the welded condition so as to expedite the final answer. 

With some materials, there are specific heat treatments that are known to reproduce the worst effects of the heat of welding. It is recommended, therefore, that in tests made to qualify a material for a particular service environment, in addition to the exposure of welded test specimens in order to observe effects of welding heat, specimens should be included that have been given a controlled abusive or sensitising heat treatment. As an illustration, austenitic stainless steels may be held at 650-700° forO-5-1 h, followed by testing for susceptibility to intercystalline attack as in ISO 3651-1 or -2 1976. 

MECHANICAL PROPERTIES OF Ti FS WELDS TESTED ALONG TRANSVERSE DIRECTION... 

Any materials (e.g., small quantity of solvent for weld-testing) deliberately introduced into the open column, as well as their containers, should be critically examined. Their evaporation may generate a hazardous atmosphere inside. The possibility of container leakage or breakage should be considered and adequately allowed for. 

Table 6.1 Results of preliminary friction stir welding testing with polycrystalline cubic boron nitride tools...

Weld metal hydrogen cracks in (a) single-run manual metal-arc fillet weld, (b) root bead of Y groove welding test, (c) submerged-arc weld (longitudinal section). 

As a first step the steel is placed in one of five grades by means of Table 4.3. These grades are based on welding tests, on studies of the continuous cooling transformation behaviour of steels, and on an empirical formula relating composition to maximum HAZ hardness ... 

A welding test conducted before beginning a major fabrication to confirm that the selected welding procedure is safe. The test wehl is designed so that material, welding consumables, joint geometry, restraint, fit-up, etc, closely resemble the details of the actual fabrication. After welding, the joints are sectioned and examined for cracks. 

Massa, G. M. (1976). Finding the optimum conditions for weld testing by magnetic particles. Nondestructive Testing International, 9, 16-26. 

The ultrasonic system has been conunissioned and tested out-of-pile using a simulated reactor weld test piece heated to 60-70 C. All of the important... 

In categorizing the various weld types, it is possible to separate these types by the time periods in which they were used. C-E qualified each particular combination of weld wire and flux lot at least one time before using a specific heat of weld material. After receiving welding wire and flux material from the suppliers, a weld test plate was prepared which used the specific combination of a heat of wire and lot of flux. This test plate was analyzed chemically and mechanically to assure compliance with all required... 

The MIRSA facility ("maquette pour interventions et reparations sous argon") which is a facility for Intervention and Repair in Argon is ready for operating. In 1995 the programme will consit in welding tests (samples wet with sodium or clean). 

ASTM G 58, Practice for Preparation of Stress Corrosion Test Specimens for Weldments— This covers the manufacture and application of welded test specimens in stress corrosion testing. This practice is used to evaluate a total weldment, weld metal, or presence of notches and stress risers in weldments with respect to SCC in an environment. In addition, ASTM G 58 contains a method for evaluating the critical stress levels that will produce SCC in a weldment. The specimens are evaluated after exposure to an environment by microscopic methods. This standard includes typical specimens (stressed and tension), welding considerations, test specimen preparation, and inspection after exposure. 

Bernstein, M. D. and L. W. Yoder. 1998. Power Boilers A Guide to Section 1 of the ASME Boiler and Pressure Vessel Code, New York American Society of Mechanical Engineers. Focuses entirely on design considerations related to power boilers and their attachments. Materials, piping, fabrication and welding, testing, inspection, certification, quality control, safety, and potential causes of damage or failure are all covered. 

FIGURE 4.118 Trial sample with 6 welding tests... 

The inquirer shall furnish complete data on the weldability of material intended for welding including data on procedure and performance qualification tests made in accordance with the requirements of Section IX. Welding tests shall be made over the full range of thickness in which the material is to be used. Pertinent information, such as heat treatment required, susceptibility to air hardening, and the amount of experience in welding the material shall be given. 

To simulate the propagation of the fronts of deconsolidation and reconsolidation associated with the welding test shown in Figure 1, transient heat... 

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