Hot-Work Die Steel Electroslag Remelted Ingot and Manufacturing Method Thereof

Abstract

The present invention discloses to a Hot-work die steel electroslag remelted ingot and a manufacture method thereof. The electroslag remelted ingot comprises the following chemical components, C: 0.36-0.41%, Si: 0.80-1.10%, Mn: 1.00-3.00%, Cr: 4.90-5.40%, Mo: 1.35-1.55%, V: 0.4-0.7%, Ni≤0.04%, Cu≤0.04%%, S≤0.003%, P≤0.012%, O≤0.0015%, H≤0.0002%, N≤0.006%, 0.05%≤RE≤0.20%, the balance being Fe. The above percentage is percentage by mass. According to the present invention, the features of electroslag remelting under inert gas protection are fully combined and a rare earth alloy is precisely fed during the electroslag remelting, thus exerting the excellent effects of RE inclusion modification and micro-alloying under high purity and high uniformity conditions and realizing high-quality and high-performance Hot-work die steel.

What is claimed is: 
     
         1 . A hot-work die steel electroslag remelted ingot, comprising the following chemical components,
 C: 0.36-0.41%, Si: 0.80-1.10%, Mn: 1.00-3.00%, Cr: 4.90-5.40%, Mo: 1.35-1.55%, V: 0.4-0.7%, Ni≤0.04%, Cu≤0.04%% S≤0.003%, P≤0.012%, O≤0.0015%, H≤0.0002%, N≤0.006%, 0.05%≤RE≤0.20%, the remaining substance being Fe, and the above percentages being percentages by mass.   
     
     
         2 . The hot-work die steel electroslag remelted ingot according to  claim 1 , wherein the RE is a binary compound of Y and La, or a binary compound of Y and Ce, or a ternary compound of Y, La, and Ce. 
     
     
         3 . The hot-work die steel electroslag remelted ingot according to  claim 2 , wherein the mass percentage of Y in the hot-work die steel electroslag remelted ingot is 0.02%≤Y≤0.15%. 
     
     
         4 . The hot-work die steel electroslag remelted ingot according to  claim 2 , wherein the mass percentage of La or Ce when present in the hot-work die steel electroslag remelted ingot is 0.015%≤La≤0.02%, 0.015%≤Ce≤0.03%. 
     
     
         5 . A method for manufacturing the hot-work die steel electroslag remelted ingot according to  claim 1 , comprising the following steps: smelting, secondary refining, vacuum degassing, die casting, and atmosphere protection electroslag remelting. 
     
     
         6 . The method for manufacturing the hot-work die steel electroslag remelted ingot according to  claim 5 , wherein the smelting is performed by using a converter smelting or an electric furnace smelting;
 the secondary refining is performed under protection of soft-blowing argon, with a time for soft blowing controlled to be 8-10 minutes, the time for vacuum degassing needs to be greater than 20 minutes; and   the die casting is performed to obtain an electrode ingot, wherein the mass percentages of O, H, and N in the electrode ingot satisfy the following conditions: O≤0.001%, H≤0.0002%, N≤0.005%.   
     
     
         7 . The method for manufacturing the hot-work die steel electroslag remelted ingot according to  claim 5 , characterized in that in the step of atmosphere protection electroslag remelting, an atmosphere protection constant melting rate electroslag remelting process is adopted, an inert gas of 2-10 ba is used for pressure protection electroslag remelting, the oxygen content in the protective cover is less than 50 ppm, and the melting rate of the electrode ingot is designed to be 500 kg/h. 
     
     
         8 . The method for manufacturing the hot-work die steel electroslag remelted ingot according to  claim 5 , wherein in the step of atmosphere protection electroslag remelting, a rare earth alloy is fed through a crystallizer feed port, the rare earth alloy being a particulate RE-Fe alloy, wherein RE accounts for 60-70% of the whole mass, Fe accounts for 30-40%, RE is one or more of La, Ce, and Y, the particle size of the rare earth alloy is 0.5-1.5 mm, and the feeding rate is 7-10 g/min. 
     
     
         9 . The method for manufacturing the hot-work die steel electroslag remelted ingot according to  claim 5 , wherein in the step of atmosphere protection electroslag remelting, a pre-molten slag is added, wherein each component in the pre-molten slag has a mass percentage of 70% CaF 2 , 15% Al 2 O 3 , 10% RE 2 O 3  and 5% MgO, and RE is one or more of La, Ce, and Y. 
     
     
         10 . The method for manufacturing the hot-work die steel electroslag remelted ingot according to  claim 9 , wherein the pre-molten slag is proportioned according to a ratio of the slag system, and then placed in an environment of 600-750° C. for continuous firing for more than 8 hours. 
     
     
         11 . The method for manufacturing the hot-work die steel electroslag remelted ingot according to  claim 10 , wherein a content of crystal water in the pre-molten slag after firing is 0.006-0.05%. 
     
     
         12 . The method for manufacturing the hot-work die steel electroslag remelted ingot according to  claim 5 , wherein the Hot-work die steel electroslag remelted ingot is subjected to forging annealing, and after forging annealing, a segregation is controlled within the AS4 grade, and a banded structure is controlled within the SA1 grade.