High-performance cold extrusion die steel and metallurgical manufacturing method thereof

Abstract

The invention provides high-performance cold extrusion die steel and metallurgical manufacturing method thereof. The high-performance cold extrusion die steel comprises the following chemical components in percentage by mass: 0.95 to 1.02 percent of C, 0.20 to 0.40 percent of Mn, 8.60 to 9.00 percent of Cr, 0.87 to 1.10 percent of Si, 1.80 to 2.00 percent of Mo, 0.40 to 0.60 percent of V, less than or equal to 0.30 percent of Cu, less than or equal to 0.25 percent of Ni, less than or equal to 0.025 percent of P, less than or equal to 0.010 percent of S, and the balance of Fe and inevitable impurities. According to the component proportion, the toughness performance of the high-performance cold extrusion die steel can be greatly improved. The metallurgical manufacturing method comprises theprocesses of electric furnace steel making, electroslag remelting and steel forging by a radial forging press. In the process of electroslag remelting, the voltage is between 57 and 59V, and the current is between11,000 and 12,000A; and in the process of steel forging by the radial forging press, steel ingots are heated to between 1,150 DEG C and 1,170 DEG C, and the temperature keeps for 2 to 4hours. The method is simple and convenient, and can remarkably improve the performance index of the steel.

Description

technical field [0001] The invention relates to a die steel, in particular to a cold extruded die steel and a metallurgical manufacturing method thereof. Background technique [0002] Die steel can usually be divided into three categories: hot work die steel, cold work die steel and plastic mold steel. The cold extrusion die steel used in the machining cold forming die used in the machining industry belongs to the three categories The cold work die steel is widely used in the manufacture of cold extrusion dies in the machining industry. The cold extrusion die steel currently used in our country is the steel grade whose material number is T21201 and steel number is Cr12MoV in the national standard GB / T1299-2000. The chemical composition of this cold extrusion die steel adopts C: 1.45-1.75wt%, Cr: 11.00-12.50wt%, Mo: 0.40-0.60wt%, V: 0.15-0.30wt%, Si≤0.40wt%, Mn ≤0.40wt%, P≤0.030wt%, S≤0.030wt%. Due to the high content of carbon and chromium in the chemical composition of t...

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Problems solved by technology

This manufacturing process has the following problems: 1) the casting ingot shape is small, which reduces the yield and manufacturing capacity of the product; 2) the electric arc furnace plus vacuum refining is directly cast into the ingot shape required for forging, and there are a large number of overlaps in the original structure of the steel ingot. Crystalline carbides and microstructure segregation reduce the performance index of the steel ingot after forging; 3) The Rockwell hardness value and impact toughness value of the material after quenching at 1040°C + tempering at 210°C and after quenching at 1080°C + tempering at 540°C are low , resulting in low-grade products, unable to meet the market's needs for high-performance cold-extrusion die steel

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