Novel low-cost free-cutting stainless steel 303B and manufacturing process thereof

The invention discloses a novel low-cost easy-cutting stainless steel 303B and a manufacturing technique thereof. The stainless steel comprises the following chemical compositions by weight percent: 0.08 to 0.15 of C, 9.00 to 11.00 of Mn, less than or equal to 0.8 of Si, less than or equal to 0.03 of P, 0.15 to 0.20 of S, 13.00 to 14.00 of Cr, 3.00 to 4.00 of Ni, 1.00 to 2.00 of Cu, and the balance of Fe and unavoidable trace impurities. A production method comprises the following steps of: primary smelting in an electric furnace, refining in a refining furnace, ingot casting, forging rollinginto blanks and heat processing of blanks. The invention contains a certain amount of Cu to guarantee corrosion resistance, simultaneously adopts low-price manganese to replace expensive nickel, reduces the cost by more than 20 percent compared with the similar product, and has processing efficiency and processed surface finish being greatly superior to Japan standard SUS303, thus particularly being applicable to manufact