Summary Recommended preheat values are based on prevention of hydrogen cracking for hydrogen contents up to 15mL/100g of weld metal The preheat values provided in AS/NZS 1554 are very conservative if low hydrogen consumables or processes are used for welding. Welding can generally be safely done with no risk of hydrogen cracking at ambient temperatures providing that H5 FCAW consumables are used, or welding is done using a low hydrogen process like GMAW. How much preheat is actually necessary for structural steel? There are 3 fundamental main reasons for preheating Prevent hydrogen cracking Prevent formation of hard HAZ Improve fusion Standards such as AS/NZS 1554.1 are used to determine the required preheat based on material group, heat input and combined joint thickness. But what is the basis for the minimum preheat temperature calculations in standards? Where did they come from? The short answer is Hydrogen Assisted Cold Cracking (HACC) prevention! The reality is t...
This paper examines what is required for competency management for welders in terms of 1) Legislative and Safety requirements 2) Technical Competency 3) Personnel Management 4) ESG There is a clear gap between current practices and what is actually required. However, the Maintenance Welder Competency provides an industry ready solution that meets all requirements, as well as satisfying QLD RS11. This paper was written by Simon Krismer from WQMS Pty Ltd for a presentation at the 2023 Queensland Mining Industry Health and Safety Conference (QMIHSC). Summary It can be very difficult to properly manage welding tradespeople on a mine site due to the inherent technical factors that must be considered regarding safety and maintenance performance. Fundamentally, this is simply because to date there have been no suitable competency assessment methods. Welding requires a mix of safety based VoC, technical competence across a range of different welding processes and repair scenarios, as wel...