Weld Quality Assessment and Control in Steel Structure Fabrication

Ling Michael^*
*Correspondence: Ling Michael, Department of Engineering Design and Materials, University of Freiburg, Fahnenbergplatz, Germany, Email:

Keywords

Welding • Fabrication • Stability

Introduction

Weld quality assessment

Weld quality assessment involves the systematic evaluation of welds to determine their conformity with specified standards and requirements. It aims to identify any defects or imperfections that may compromise the structural integrity and long-term performance of the steel structure. Various techniques and methods are employed during weld quality assessment, including visual inspection, Non-Destructive Testing (NDT) and destructive testing. Visual inspection is the most basic yet fundamental method used to assess weld quality [1]. It involves a careful visual examination of the weld and its surrounding area for visible defects such as cracks, incomplete penetration, porosity, undercutting and weld profile irregularities. Well-trained inspectors with a keen eye for detail are essential for accurate visual inspection.

Non-Destructive Testing methods are widely employed to assess weld quality without causing damage to the structure. These techniques include radiography, ultrasonic testing, magnetic particle inspection, liquid penetrant testing and eddy current testing. NDT methods provide valuable information about internal defects, discontinuities and material properties, helping to ensure weld quality and integrity. Destructive Testing is necessary to evaluate weld quality. This involves removing representative samples from the welded joints and subjecting them to various tests, such as tensile testing, bend testing, impact testing and hardness testing [2]. Destructive testing helps assess mechanical properties, such as strength and toughness and ensures compliance with design specifications and welding standards.

Literature Review

Weld quality control

Weld quality control encompasses a range of activities aimed at preventing, detecting and mitigating welding defects during the fabrication process. It involves implementing stringent procedures and standards to maintain the desired quality level consistently. A well-defined Welding Procedure Specification is crucial for controlling weld quality. It outlines the specific welding parameters, techniques and materials required for each joint, ensuring consistency and repeatability. WPS considers factors such as welding process, electrode type, preheat temperature, interpass temperature and post-weld heat treatment, based on the structural requirements and applicable welding codes [3]. Skilled and qualified welders are vital for achieving high-quality welds. They must possess the necessary certifications and experience in the specific welding processes and techniques employed in steel structure fabrication. Welding operators should be knowledgeable about the WPS and proficient in executing the required welds with precision.

Regular inspection and supervision of the welding process are critical to ensuring adherence to quality standards. Qualified inspectors and supervisors should monitor the welding operations, verify compliance with the WPS and address any deviations or issues promptly. They should also perform intermittent NDT to detect defects and take corrective measures as required. Controlling the quality of base materials and consumables, such as welding electrodes and filler wires, is essential for weld quality control. Proper storage, handling and verification of materials before use are crucial to prevent contamination, improper heat treatment, or mismatched materials that can lead to weld defects [4]. Continuous training and education of welders, inspectors and other personnel involved in steel structure fabrication are vital for maintaining high weld quality. Keeping up with the latest welding standards, techniques and best practices helps improve skills and knowledge, leading to better weld quality and productivity.

Discussion

The fabrication of steel structures

The first step is the design and engineering phase, where architects and engineers collaborate to create the structural design. This includes determining the dimensions, load-bearing capacity, and overall layout of the steel structure. Computer-Aided Design (CAD) software is often utilized to create detailed 3D models and drawings. Once the design is finalized, the necessary steel materials are procured. This involves sourcing the required steel sections, plates and other components from suppliers. Quality control measures are implemented to ensure that the materials meet the required specifications and standards [5]. The steel components are then cut and shaped according to the design specifications. This is typically done using specialized tools such as saws, shears and plasma cutters. The cutting process may involve straight cuts, beveling, or complex shapes depending on the design requirements.

Welding is a fundamental process in steel structure fabrication. It involves joining steel components together using various welding techniques, such as arc welding, MIG welding, TIG welding, or submerged arc welding. Skilled welders follow approved welding procedures to ensure strong and reliable connections. Prior to assembly, the steel components undergo surface preparation to remove any rust, scale, or contaminants. This is essential for ensuring proper adhesion during the coating application process. Surface preparation methods include abrasive blasting, grinding, or chemical cleaning. Steel structures are often coated to protect them from corrosion and enhance their appearance. Common coating methods include the application of primer, paint, or specialized protective coatings [6]. The coating process is typically performed in controlled environments to achieve the desired finish and ensure long-term durability.

Once the individual steel components are ready, they are transported to the construction site for assembly and erection. Cranes and other lifting equipment are used to position and connect the steel sections according to the design plans. Skilled ironworkers and construction team work together to ensure proper alignment and secure connections. Throughout the fabrication process, quality assurance and inspection procedures are implemented to verify compliance with the design specifications and industry standards. Visual inspections, Nondestructive Testing (NDT) and destructive testing may be conducted to assess weld quality, material strength and overall structural integrity. After the steel structure is erected, additional components and systems, such as roofing, cladding, HVAC (heating, ventilation and air conditioning) and electrical systems, are installed and integrated into the structure. This stage involves coordination among various trades to complete the construction project.

Conclusion

Weld quality assessment and control are indispensable in steel structure fabrication to ensure the reliability, safety and durability of the final product. By employing rigorous inspection techniques, such as visual inspection, NDT and destructive testing, weld defects can be identified and rectified promptly. Implementing robust quality control measures, including well-defined WPS, qualified personnel, inspection and material control, helps prevent defects and ensures consistent weld quality throughout the fabrication process. By prioritizing weld quality assessment and control, steel structure fabricators can deliver structures that meet or exceed the required standards, providing long-lasting and secure infrastructure for various applications. Steel structure fabrication requires skilled professionals, advanced equipment and adherence to strict quality control procedures to ensure the structural integrity, safety and longevity of the final product. Proper fabrication practices result in robust steel structures that can withstand various environmental conditions and serve as reliable infrastructure for a wide range of applications.

Acknowledgement

None.

Conflict of Interest

None.

References

1. Pereira, António B and Francisco JMQ de Melo. "Quality assessment and process management of welded joints in metal construction—A review." Metals 10 (2020): 115.

Google Scholar, Crossref, Indexed at

2. Skriko, Tuomas, Antti Ahola and Timo Björk. "Overview on the digitized production of welded steel structures." World Weld 66 (2022): 799-813.

Google Scholar, Crossref, Indexed at

3. Amirafshari, Peyman and Athanasios Kolios. "Estimation of weld defects size distributions, rates and probability of detections in fabrication yards using a Bayesian theorem approach." Int J Fatigue 159 (2022): 106763.

Google Scholar, Crossref

4. Darji, Raghavendra, Vishvesh Badheka, Kush Mehta and Jaydeep Joshi, et al. "Investigation on stability of weld morphology, microstructure of processed zones and weld quality assessment for hot wire gas tungsten arc welding of electrolytic tough pitch copper." Mater Manuf Process 37 (2022): 908-920.

Google Scholar, Crossref, Indexed at

5. Zhang, Lu, Alexandra Carmen Basantes-Defaz, Didem Ozevin and Ernesto Indacochea. "Real-time monitoring of welding process using air-coupled ultrasonics and acoustic emission." J Adv Manuf Technol 101 (2019): 1623-1634.

Google Scholar, Crossref, Indexed at

6. Amirafshari, Peyman, Nigel Barltrop, Martyn Wright and Athanasios Kolios. "Weld defect frequency, size statistics and probabilistic models for ship structures." Int J Fatigue 145 (2021): 106069.

Google Scholar, Crossref, Indexed at