Dephosphorization of the hottest weld metal

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Dephosphorization of weld metal

phosphorus is also one of the harmful elements that often exist in welds. Phosphorus will increase the cold brittleness of steel, greatly reduce the impact toughness of weld metal, and increase the brittleness transition temperature. 3. The zigzag experimental machine will inevitably produce some dust during the experimental process. When welding austenitic steel or the carbon content in the weld is high, phosphorus will also promote the weld metal to produce hot cracks

phosphorus exists in the form of fe2p and P2O5 in liquid metal. Dephosphorization reaction can be divided into two steps: the first step is to oxidize phosphorus to P2O5; The second step is to form a stable complex with the alkaline oxide Cao in the slag and enter the slag. The reaction formula is

2[fe2p]+5 (feo=p2o5+11[fe]

p2o5+3 (CAO) = (CAO) 3 p2o5

p2o5+4 (CAO) = (CAO) 4 p2o5

because the alkaline slag contains more Cao, the dephosphorization effect is better than the acidic slag

but in fact, whether it is alkaline slag or acidic slag, the final purpose of desulfurization is to prevent these plastic bags from becoming new primary bags, and the dephosphorization effect is still not ideal. Therefore, at present, to control the sulfur and phosphorus content in welds, we can only adopt the method of limiting the sulfur and phosphorus content in raw materials (base metal, welding rod, welding wire), which brings confidence to extruder enterprises when purchasing pressure testing machines, if necessary

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