Alloy steel and manufacturing method thereof

• Main Authors: LI QINGCHUN, DAI HUAYUN, LI JUN, CHEN XIAOLONG, KE XIAOTAO, LEI XIUHUA, LIU MING, YANG WENZHONG
• Format: Patent
• Language: Chinese; English
• Published: 27.04.2011
• Subjects: ALLOYS; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; METALLURGY; METALLURGY OF IRON; PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OFWROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

The invention provides an alloy steel and a manufacturing method thereof. The manufacturing method comprises the steps of: primarily smelting steel into molten steel; when the C content of the molten steel is 0.03-0.06 percent, the P content is not more than 0.015 percent and the S content is not more than 0.020 percent, tapping a steel ladle; during tapping, regulating the Si content of the molten steel to be 0.17-0.37 percent, Mn content to be 0.40-0.70 percent, Cr content to be 0.80-1.10 percent and Mo content to be 0.40-0.55 percent, and regulating the oxygen content of the molten steel to be below 0.0020 percent; controlling the Als content of the molten steel to be 0.02-0.0 percent, wherein Als represents acid-soluble aluminium; ensuring that the oxygen content is below 0.0010 percent when the molten steel is refined and the C content of the molten steel is 0.12-0.18 percent after the refining is ended in a steel ladle refining furnace; and carrying out circulating vacuum degassing treatment on the molt