Introduction
Testing a product or component is an important step in the production or maintenance process of such a product. Apart from identifying issues and defects in the components, it gives room for an unbiased and wholesome review of the components. That way, the designers and manufacturers will correct these defects and prevent their occurrence in the future. Welds and welded components are one of the components that require testing and inspection.
There are many ways of inspecting welds and welded components. Most of these methods of inspection require partial or total destruction of the component to be inspected. Thus, rather than correct the observed anomalies, another component will have to be manufactured, while bearing the corrections in mind. This is an expensive method of inspection, hence the introduction of the X ray Welding Inspection System.
In this article, the digital X ray Inspection System will be discussed. The inspection system’s need and how to use the X ray welding inspection system will also be examined.
Why We Need X-Ray Inspection For Weld?
Types of Flaws in Welds
Welding is one of the safest and secure ways of joining pipes and other engineering components. It has long been in use in the engineering industry for many years. However, despite its efficiency, some flaws could occur in welded components. These flaws, which they do not concur with industry standards, are referred to as defects or discontinuities. Some of these flaws are:
Cold Lap: This occurs when there is no proper fusion between the base metal and the weld filler metal. It is usually caused when the heat from the arc doesn’t melt the base metal properly, thus causing some molten puddle to flow into the base material. This results in non-bonding.
Porosity: This flaw refers to holes along the surface of the weld. This is usually caused by the entrapment of gas in the solidifying metal. The X ray welding inspection allows you to see this defect in numerous ways. These include irregular spots and elongated lines.
Cluster Porosity: This flaw is usually as a result of moisture contaminating the flux coated electrodes. This contamination leads to the conversion of the moisture to gas, causing another entrapment. This entrapment leads to holes and voids in the weld.
Slag Incursions: This refers to material lodged in between the base material and weld. In some other cases, the material, usually non-metallic, is entrapped between the base metal and the weld filler metal.
Lack of penetration: This flaw is caused by the inability of weld metal to penetrate the joint. This lack of penetrating causes a crack in the component as a natural stress riser usually occurs from the flaw.
Internal Concavity: In this defect, the weld material cools after welding, thereby contracting. This contraction is drawn into the root of the weld.
Root Undercut: This refers to the erosion or continuous removal of the base metal situated next to the weld’s root.
External Undercut: another variant of undercut in which the erosion of the base metal occurs near the crown of the weld.
Burn Through: this occurs when there is too much heat from the arc, causing the excess weld metal to enter the weld zone.
These are some of the flaws that can be found in welded components. These flaws and many more can be identified using the X ray welding Inspection system.
Why We Need An X-Ray Inspection For Weld?
X ray inspection is a testing method that uses radiographic rays for the inspection of components. The X ray inspection system is needed because it provides one of the best testing and inspection methods. This is because engineers and welders using it don’t have to alter or destroy the welded component before checking for flaws. The X ray provides a clear and detailed representation of the internal structure of the components. These are some of the major reasons why the X ray weld inspection method is used for inspecting welded components.
Advantages of Digital X-ray Systems for Weld Inspection
The following are the advantages of using an X ray welding inspection system
● A quick inspection of components. The X ray welding inspection system is one of the fastest inspection systems in the industry
● It allows you to carry out inspection of ultrasonic indications
● It also allows the replacement of the film when inspecting the ends of the pipe.
Important Considerations in X-Ray Testing of Welds
The following are the criteria you must consider whenever you are using the xray weld inspection method.
Accuracy and Precision
The very essence of testing rests on these two factors. Accuracy refers to the degree of correctness of the test result to the actual flaw, while precision refers to the ability to reproduce the test results. These factors must be ticked before applying the X ray welding inspection method.
The Strength and Weakness of the Method
Every testing methods have inherent merits and demerits. You must be sure that the X Ray welding inspection has more advantages than demerits for your applications.
Absoluteness of the method
This factor implies that you ask if the X ray inspection method is the only method that will be needed. Some testing procedures require the combination of other methods to achieve a near accurate result. Using an absolute method saves costs and time, provided that the results are accurate and precise.
Conclusion
Radiographic inspection of welds is an effective way of identifying issues and defects so as to correct them and prevent their occurrence in welded joints and welded components in general.