DETERMINATION OF FACTORS AFFECTING THE STABILITY OF WELDED TIPS OF OXYGEN LANCE
Bibliographic record
Abstract
It has been established that the most likely cause of crack formation is differences in the chemical composition of the welding wire, the material of the Laval nozzle and the outer cage of the lance tip. For example, the difference in copper content is 6.79%. The microstructures of the weld, Laval nozzle metal, and outer lance tip rim were analyzed and compared along the cross section of the weld location. Microcracks located along the grain boundaries were detected, which is probably due to the appearance of weak compounds with low ductility and non-propagation at the grain boundaries. In the structure of welds, accumulations of oxygen inclusions along the boundaries of crystallites were found, which leads to copper embrittlement and can contribute to weld failure. Freezing a layer of converter slag with low thermal conductivity on the tip surface reduces the thermal conductivity of the formed slag metal layer and heat transfer to the cooling water. Even if there is a 1 mm layer of slag on the surface of the weld, thermal conductivity decreases by 79-95%, depending on the thickness of the slag and its properties, respectively. If there is a layer of slag on the surface of the weld, the heat transfer decreases by 51-56% (at 1 mm of slag) and by 72-88% at 20 mm, respectively.In order to prevent the formation of cracks between the Laval nozzle and the outer cage of thehandpiece, it is advisable to follow the following recommendations when performing welding operations. In the simplest case, the first welded layer should be performed using a non-consumable electrode (tungsten or graphite) in an argon or helium atmosphere, which will ensure the formation of a reliable, tight weld around the entire circumference of the nozzle. To reduce stresses in the weld, subsequent welded layers should be performed in alternating directions. A more effective option is the technology according to which, after the first weld is applied, the nozzle is connected to the tip from the inside with a partial (discrete) or continuous weld, which minimizes the likelihood of failures and can ensure the sealing of the tip when the initial cross-section of the Laval nozzles increases to the critical ignition diameter. The implementation of an internal weld will reduce mechanical loads on the external weld, especially when using metal hose expansion joints, and increase the strength of the welded joint as a whole.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".