MAGMA presents with the latest software version MAGMASOFT® 5.4, a comprehensive toolbox of new capabilities for the optimization of casting designs, tooling.

Streaming bokep archives selingkuh terupdate asian sex diary. First Core Blowing Test. The bottom of the core collapsed due to a lack of strength. Brazilian steel giant Usiminas recently introduced the new foundry core making simulation software MAGMASOFT® as part of their strategy to establish robust designs and processes for their core production line. The first project on which this software was utilized was already in progress at that time. The main goal was to optimize the process conditions for the existing tooling layout. This core, called the thin waist core, represents some of the biggest challenges for Usiminas core production: its length (920 mm), substantial changes in the sand flow direction during blowing, the need to fill certain parts of the core through counter-flow and big variations in the cross section within the core.

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First trials showed problems with the process, which led to a complete collapse of the lower part of the core. The core blowing and curing steps for the PU coldbox process were analyzed, making it possible to draw preliminary conclusions regarding the existing defects. Curing Gas Concentration. The curing gas does not penetrate into the core to the same extent everywhere. The lack of core strength was related to a poor curing process.

The first simulation (Figure 2) already showed that the problematic regions experienced only very low curing gas concentrations during gassing, which was the root cause for the failure. On the production line, various process conditions such as the curing and purging times and gassing pressure were changed. These attempts provided better results (Figure 3).

However, a perfect core could still not be produced. The further analysis with MAGMASOFT® focused on the evaluation of the local concentration of adsorbed curing gas, as it shows the regions where the catalyzing gassing agent cannot activate the chemical reaction. This result clearly demonstrated that only a very small quantity of catalyst was available for accelerating curing in the defect regions (Figure 3). Core Blown with new parameters in comparison with the local concentration of adsorbed curing gas. The problematic area corresponds exactly with low concentrations in the simulation. Evaluating simulated curves for the gas mass flow through the vents made it clear that the catalyzing gas was not reaching the critical area.

The open venting cross section of the top and central vents was allowing the gas to escape before it reached the bottom of the core. Instead of making costly modifications to the core box, Usiminas determined that a possible – and simple – solution was to close some vents in the top and center regions, in order to increase the gas concentration in the bottom. However, it was clear that these changes obviously would also influence the core blowing step. The optimization led to a considerable increase of the curing gas concentration in the lower regions of the core (~36%) (Figure 4). Also, the amount of adsorbed curing gas increased in comparison to the original project. Applying these modifications, Usiminas produced another core, which did not show any gassing defects.

Since the venting area was reduced, some filling defects were present, as expected. Total gas mass flow through the lower vents. The change in mass flow becomes clear. Removing some of the upper and middle vents resulted in a 36% increase in the gas escaping through the lower vents. Having solved the curing related defects, a further core blowing analysis was carried out. The simulation results showed a very good match between the real defects and areas of low packing density.