The invention relates to a low-cost, high-strength, high-
toughness and high-abrasion resistance
alloy steel and a preparation method thereof. The invention belongs to the technical field of preparation technologies of special
alloy steel. The
alloy steel comprises the following elements by weight percent: 0.88-1.10% of C, 0.45-0.65% of Si, 0.20-0.50% of Mn, 7.50-9.0% of Cr, 1.30-1.80% of Mn, 0.30-0.60% of V and the balance of Fe. The preparation process comprises the following steps: (1) preparing materials and melting by using the conventional method, wherein the
melting temperature is 1500-1550 DEG C; (2) carrying out electro-
slag re-melting; (3) annealing after the electro-
slag re-melting; (4)
forging; (5) annealing after the
forging, and annealing at the temperature of 850-880 DEG C for 8 hours; (6) carrying out shpheroidizing annealing to 860-550 DEG C; and (7) carrying out the heat treatment technology, adopting the low temperature
quenching and low temperature
tempering or high temperature
quenching and high temperature
tempering technology for carrying out heat treatment, and finally preparing the high-strength, high-
toughness and high-abrasion resistance cold-working die steel. The
hardness of the die steel is 62-63HRC and the average
impact toughness is 80J. Compared with the imparted steel, the
alloy steel has the equivalent
hardness and toughness, and can completely replace the imported high-strength, high-toughness and high-abrasion resistance cold-working die steel.