High manganese austenitic iron-based alloy containing boron

The invention relates to a high manganese austenitic iron-based alloy containing boron and a thermal processing method thereof. The alloy comprises the following chemical components of: 0.15-0.40% of C, 0.5-1.5% of Si, 8.0-14.0% of Mn, 15-22% of Cr, 1.5-3.5% of Ni, 0.3-0.55% of Nb, 0.4-0.5% of N+B and the balance being F2 and inevitable impurities. The normal temperature hardness of a cast alloy of the alloy melted by an electric furnace and shaped by centrifugally casting is up to 25-30 HRC; the room temperature extension strength is up to 700-720 MPa; the impact tenacity is up to more than 22 J/cm ; the corrosion resisting life is improved by 2.5-3 times more than a 316L stainless steel. Furthermore, the invention provides a thermal processing method for improving the corrosion resistance of the alloy, comprising the following steps of: completely solidly dissolving and separating secondary boride compounds in the issue via the high temperature solidly dissolving treatment and the annealing treatment so tha