LOW-STEEL-GRADE PIPELINE CLEAN STEEL AND SMELTING PROCESS THEREFOR

摘要

Disclosed is a low-steel-grade pipeline clean steel, relating to the technical field of metallurgy. The low-steel-grade pipeline clean steel has the following chemical ingredients and mass percentages thereof: C: 0.04-0.07％, Si: 0.10-0.35％, Mn: 1.00-1.50％, P≤0.015％, S: 0.0020-0.0050％, Nb: 0.030-0.070％, Ti: 0.006-0.020％, Ni≤0.30％, Cr≤0.30％, Cu≤0.30％, Al: 0.015-0.050％, and the balance being Fe and impurities. In the invention, an accurate system analysis is carried out on a formation control mechanism of inclusions, a reasonable component design is adopted, a calcium treatment process is carried out after an RH vacuum treatment, and the degree of superheating is reasonably controlled, such that the purpose of improving the purity of the molten steel is achieved, the internal quality of the steel is improved, and the economic benefits are improved.