Refining Process of X80 Pipeline Steel

X80 pipeline steel has very strict requirements on the control of harmful elements and inclusions in the steel. In production, the production process of refining outside the furnace is often used to ensure the purity of X80 pipeline steel. The refining equipment outside the furnace mainly includes LF furnace, RH and VD. The main refining processes are LF-RH and LF-VD.

LF has strong desulfurization ability. However, its desulfurization ability and process nitrogen increase control will be affected by subsequent degassing and refining methods; VD has strong denitrification and desulfurization capabilities, but its desulfurization effect is restricted by the upstream LF refining slag, and it also affects LF. The control of slag desulfurization and nitrogen increase has obvious influence; RH refining has a strong ability to dehydrogenate and remove inclusions.

X80 pipeline steel can be produced by the above three refining processes, but X80 pipeline steel with higher purity and cleanliness can be produced by using the LF-RH refining process. In the LF-RH refining process, RH will cause secondary oxidation of the X80 pipeline molten steel, and AI2O3 inclusions will appear in the X80 pipeline steel, so it is necessary to perform calcium treatment on the X80 pipeline molten steel after RH refining.