Carbon steel and manufacturing method

The invention provides carbon steel and a manufacturing method thereof. The manufacturing method comprises the following steps of: refining liquid steel primarily; tapping from a steel ladle when the carbon (C) content of the liquid steel is 0.05 to 0.10 percent, the phosphorus (P) content of the liquid steel is not more than 0.015 percent and the sulfur (S) content of the liquid steel is not more than 0.020 percent; in the tapping process, adjusting the silicon (Si) content of the liquid steel to be 0.17 to 0.37 percent, the manganese (Mn) content of the liquid steel to be 0.35 to 0.65 percent and the oxygen content of the liquid steel to be below 0.0020 percent; controlling the acid-soluble aluminium (Als) content of the liquid steel to be 0.02 to 0.03 percent; adjusting the oxygen content of the liquid steel to be below 0.0010 percent in a steel ladle refining furnace and adjusting the C content of the liquid steel to be 0.17 to 0.23 percent; and performing circulating vacuum degassing treatment on the liquid steel and adjusting the titanium (Ti) content of the liquid steel to be 0.006 to 0.010 percent so as to obtain the carbon steel. The carbon steel comprises the following elements in percentage by weight: 0.17 to 0.23 percent of C, 0.17 to 0.37 percent of Si, 0.35 to 0.65 percent of Mn, 0.006 to 0.010 percent of Ti, 0.008 to 0.015 percent of Als and the balance of ferrum (Fe) and inevitable impurities.