N80 Tubing Steel Smelting Non-quenched And Increasing Nitrogen Mathematical Model

Non-quenched and tempered steel has the advantage that the working procedure is shortened, the material ration is high, the component quality is improved, energy consumption and production cost is lowered because it is not produced by the process of hardening and temper. In the result, non-quenched and tempered steel is fully applied. Nitrogen is blowed into the liquid steel and carried on the nitrogen of alloy, it may reduce the cost of non-quenched and tempered steel N80 oil pipe. This paper is made a commercial test of non-quenched and tempered steel N80 oil pipe in Angang converter. And the theory analyses the condition that steel fliud attracts the nitrogen under the atmosphere and the slag cover; steel fluid attracts the nitrogen in the process of the ladle bottom blowing nitrogen.The result shows that attracting nitrogen speed has the decisive influence on steel fluid deaeration condition.When steel fluid deaeration is good and dissolved oxygen content is low, attracting nitrogen speed is high, attracting nitrogen is the first level of response; When steel fluid is not deaerated and its attracting nitrogen speed is low, attracts attracting nitrogen is the second level of response; The covered slag reduces steel fluid attracting nitrogen speed. According to steel fluid attracting nitrogen thermodynamics and the kinetic theory, the mode of nitrogen content control mathematical in the blowing nitrogen process after VD is not in the vacuum is established, nitrogen content at steel fluid end point is carried on forecast, the effect factors on the nitrogen are analysed. The converter process of non- quenched and tempered oil pipe is optimized. The model computation and the commercial test result indicated that the containing nitrogen low-alloy structural steel carrying on the nitrogen alloy produce non-quenched and tempered steel N80 oil pipe, may increase steel fluid the nitrogen content to its specification ingredient scope.