Steel structures, like anything else that is manufactured, need to be tested for strength and hardness in order to make sure there are not any critical errors or failures in the structure. Non-destructive testing is an economical and effective solution to find the strength of steel structure and its joints, such as welds. This is not only a good idea for new construction, but Non-destructive testing (NDT) is also a test that allows for the evaluation of the quality of materials used for the fabrication of steel and concrete structures of existing buildings as well. Let’s explore some of the advantages and types of NDT testing for steel construction.
Advantages Of NDT testing for Steel Construction.
There are several great advantages to NDT testing of steel-constructed structures. By using non-destructive testing, the condition of existing buildings can be determined, from purely a maintenance standpoint or after an issue like a natural disaster. Engineers and builders can avoid costly repairs by ensuring the integrity and strength of the structural elements and spotting issues that could be more easily solved after testing instead of waiting.
On newer and older buildings, the structural elements such as the steel can be verified to be up to code. ASTM provides technical standards and codes for the quality of materials, products, and systems, and serves as a guide when evaluating the design and fabrication of a steel or concrete structure.
Types of NDT testing for Steel Construction
Magnetic Particle Testing
Magnetic Particle inspection is a non-destructive test that detects surface and shallow subsurface flaws in ferromagnetic material. This test is a very effective method for determining the location of surface-breaking and slightly sub-surface defects such as cracks, pores, cold lap, lack of sidewall fusion in welds, etc. in magnetic materials. They magnetize the test area, then apply the magnetic particles to the surface. The presence of surface or subsurface discontinuity allows the magnetic flux to leak.
Ultrasonic Hardness Testing is also known as Ultrasonic Contact Impedance. The Ultrasonic Contact Impedance method has been around for over 50 years and was developed for heavy and/or unmovable parts where traditional testing methods could not be used or would take great difficulty to use. This makes it a great type of non-destructive testing for steel construction. For example, ultrasonic thickness gauging helps inspect the thickness of structural steel. This can measure the metal loss by corrosion, erosion, or damage. An ultrasonic thickness gauge works by precisely measuring how long it takes for a sound pulse that has been generated by a small probe called an ultrasonic transducer to travel through a test piece and reflect back from the inside surface or far wall.
Another way of using ultrasonic testing is using it on welds and steel plates. Ultrasonic waves are transmitted through the material to detect internal flaws of the material. Ultrasonic waves are directional, and they will travel through a medium that is being tested until they encounter a boundary with another medium. That is when they reflect back to their source. This can be used to find the thickness of a material or a crack in the piece.
Liquid penetration test
Liquid penetrant inspection (LPI), also called fluorescent penetrant inspection (FPI) or penetrant testing (PT) uses supplies like the Spotcheck® Penetrant Kits to inspect surface-breaking defects in non-porous materials. This includes checking for material flaws on the surface of structural steel. This test can be used on non-metallic materials as well. The penetrant is applied to the surface that is to be tested and remains there for a sufficient time in order to allow the liquid to penetrate into any defects open at the surface. After sufficient time, the excess penetrant, which remains on the surface, is removed. Then a dry type or wet type of developer is applied to the surface. The developer helps draw out the indications if there are surface cracks.
If you or your company builds or repairs steel structures, some of the methods probably are familiar. If you are looking for a reliable source for your NDT testing supplies, METSUCO has been supplying a number of industries over the past 30-plus years with affordable and reliable non-destructive testing supplies and equipment. For most orders, we can provide a quote in less than 24 hours and even offer samples on many of our products. Please call 713-827-0700 or email email@example.com.