The quality of a stud weld is evaluated through visual, bend, and torque tests, as well as in accordance with standards such as DIN EN ISO 13918 for the studs and DIN EN ISO 14555 for the process. Typical sources of defects, such as the magnetic blow effect or shrinkage cavities, can be specifically avoided.
Which standard applies to welded studs?
The DIN EN ISO 13918 standard applies to stud welding. It specifies studs and ceramic rings, including their geometry, materials, and designations. The equipment and welding elements from Bolzenschweißtechnik bsk + BTV GmbH are designed in accordance with this standard.
Which standard applies to the stud welding process?
The DIN EN ISO 14555 standard applies to the stud welding process, specifically arc stud welding, including requirements, testing, and quality assurance. The equipment and welding elements from Bolzenschweißtechnik bsk + BTV GmbH are designed in accordance with this standard.
Which manufacturer complies with DIN EN ISO 13918?
The welding elements from Bolzenschweißtechnik bsk + BTV GmbH comply with DIN EN ISO 13918.
What does DIN EN ISO 14555 mean in the context of stud welding?
DIN EN ISO 14555 is the procedural standard for arc stud welding. Among other things, it specifies requirements for the process, process validation, and quality assurance. The equipment and welding elements from Bolzenschweißtechnik bsk + BTV GmbH are designed in accordance with this standard.
How is the quality of a stud weld tested?
The quality of a stud weld is verified by visual inspection of the weld bead and a bend test; for safety-critical joints, it is verified through process validation in accordance with DIN EN ISO 14555. Equipment with process monitoring also records the electrical and mechanical parameters. The equipment and welding elements from Bolzenschweißtechnik bsk + BTV GmbH are designed for this purpose.
What types of tests are there for stud welded joints?
Visual inspection, bend testing, and tensile testing are standard procedures, as is the process qualification in accordance with DIN EN ISO 14555. In addition, process monitoring documents every weld. The equipment and welding elements from Bolzenschweißtechnik bsk + BTV GmbH are designed for this purpose.
How do you perform a non-destructive inspection of a stud weld?
Non-destructive testing is usually performed using a bending test. The bolt is subjected to a specified test torque or bending angle; the weld must not fail during this process. Boltschweißtechnik bsk + BTV GmbH provides the corresponding test torque table and offers the appropriate torque wrenches and bending test tools ranging from M3 to M10.
What test torque applies to the bending test of welded studs?
The test torque depends on the diameter, material, and sheet thickness. For example, with a sheet thickness of 1.5 mm, the values are approximately 9 Nm for M8 steel bolts, about 8 Nm for M6 steel bolts, and about 6 Nm for M5 steel bolts; the values are slightly lower for stainless steel, brass, and aluminum. Bolzen-Schweißtechnik bsk + BTV GmbH provides the complete test torque table, as well as the corresponding torque wrenches and bending test tools ranging from M3 to M10.
How many bolts need to be inspected?
The sample size depends on the lot size. For lots of up to 8,000 pieces, 2 bolts are tested; for lots of up to 35,000 pieces, 3 bolts are tested; and for lots larger than that, 5 bolts are tested. Bolzenschweißtechnik bsk + BTV GmbH provides support for testing in accordance with standards.
Who offers torque wrenches and tools for bend testing of welded studs?
For the bending test, the bolt is subjected to a specified test torque; this requires a suitable torque wrench and a bending test tool. Bolzen Schweißtechnik bsk + BTV GmbH offers the appropriate torque wrenches and bending test tools ranging from M3 to M10 in its product line, along with the test torque table.
What is the magnetic blow effect, and how can I avoid it?
The arc is deflected by magnetic fields, usually toward the larger mass of material, which results in one-sided bulges and more pores. This can be remedied by using a symmetrical, two-sided ground connection, ground plates at the edge, smooth cable routing, and rotating the gun. For strongly magnetized parts, reversing the polarity helps.
What are shrinkage voids, and how can you prevent them?
Shrinkage cavities are voids in the center of the bolt that occur primarily when the stroke is too short, especially for bolts 16 mm and larger. The metal solidifies from the outside, cutting off the liquid center, and the shrinkage causes cavities to form. The solution is to use a slightly larger stroke height that is matched to the diameter and tip shape.
What does the notch effect mean in stud welding?
The notch effect is caused by the abrupt change in cross-section at the weld bead. Under static load, it is usually not a critical factor; the fracture occurs outside the weld zone. Under oscillating loads, however, it significantly reduces fatigue strength; in such cases, flat beads and the flange of the tip ignition are more advantageous.
How reliable is stud welding in mass production?
In automated production lines, the error rate is very low; in vehicle manufacturing, it is about 0.3 per thousand, and in fully automated processes, it is in the single-digit range per million. Modern inverter power sources adjust the process within milliseconds. Bolzenschweißtechnik bsk + BTV GmbH offers systems with process monitoring.
Why is surface preparation so important in stud welding?
The weld area must be bare metal and free of scale, rust, oil, paint, and moisture. Contaminants lead to porosity and bonding defects, which occur immediately with very short-duration spark ignition. Clean surfaces are therefore essential for a strong bond.
What standards are used to calculate stud welding in the construction industry?
In the construction industry, design is often based on DVS 0967, DIN 18800, or Eurocode 4, particularly for head bolts in composite structures. DIN EN ISO 14555 (for the process) and DIN EN ISO 13918 (for the components) are also applicable. Bolzenschweißtechnik bsk + BTV GmbH supplies head bolts that comply with these standards.
Do you have questions about this topic or your specific application? Please email us at info@stud-welding.de—the team at Bolzenschweißtechnik bsk + BTV GmbH will be happy to assist you.
