Heat-resistant cast steel, and preparation method and use thereof

Abstract

The present invention provides a heat-resistant cast steel, and a preparation method and use thereof. Based on the total mass of the heat-resistant cast steel, the heat-resistant cast steel includes the following elements in mass percentage: 0.08 wt %-0.18 wt % of C, 0.10 wt %-0.40 wt % of Si, 0.30 wt %-0.70 wt % of Mn, 9.80 wt %-10.70 wt % of Cr, 3.00 wt %-3.50 wt % of Co, 1.60 wt %-2.00 wt % of W, 0.45 wt %-0.85 wt % of Mo, 0.10 wt %-0.30 wt % of V, 0.02 wt %-0.08 wt % of Nb, 0.010 wt %-0.035 wt % of N, 0.001 wt %-0.010 wt % of B, <0.20 wt % of Ni and 79 wt %-85.5 wt % of Fe. The heat-resistant cast steel can satisfy the use requirements of turbine parts with a working temperature of 635° C. and below 635° C.

1 . A heat-resistant cast steel, wherein based on the total mass of the heat-resistant cast steel, the heat-resistant cast steel comprises the following elements in mass percentage:
 0.08 wt %-0.18 wt % of C, 0.10 wt %-0.40 wt % of Si, 0.30 wt %-0.70 wt % of Mn, 9.80 wt %-10.70 wt % of Cr, 3.00 wt %-3.50 wt % of Co, 1.60 wt %-2.00 wt % of W, 0.45 wt %-0.85 wt % of Mo, 0.10 wt %-0.30 wt % of V, 0.02 wt %-0.08 wt % of Nb, 0.010 wt %-0.035 wt % of N, 0.001 wt %-0.010 wt % of B, ≤0.20 wt % of Ni and 79 wt %-85.5 wt % of Fe.   
     
     
         2 . The heat-resistant cast steel according to  claim 1 , wherein the heat-resistant cast steel further contains impurities, comprising one or more of Al, P, S, Cu, Ti and Sn. 
     
     
         3 . The heat-resistant cast steel according to  claim 2 , wherein based on the total mass of the heat-resistant cast steel, the corresponding mass percentages of Al, P, S, Cu, Ti and Sn are: ≤0.030 wt % of Al, ≤0.030 wt % of P, ≤0.020 wt % of S, ≤0.25 wt % of Cu, ≤0.030 wt % of Ti and ≤0.030 wt % of Sn. 
     
     
         4 . The heat-resistant cast steel according to  claim 1 , wherein based on the total mass of the heat-resistant cast steel, the heat-resistant cast steel comprises the following elements in mass percentage: 0.10 wt %-0.16 wt % of C, 0.20 wt %-0.30 wt % of Si, 0.40 wt %-0.60 wt % of Mn, 10.00 wt %-10.50 wt % of Cr, 3.10 wt %-3.40 wt % of Co, 1.65 wt %-1.90 wt % of W, 0.55 wt %-0.75 wt % of Mo, 0.15 wt %-0.25 wt % of V, 0.03 wt %-0.07 wt % of Nb, 0.015 wt %-0.030 wt % of N, 0.002 wt %-0.008 wt % of B, ≤0.10 wt % of Ni and 81 wt %-83.8 wt % of Fe. 
     
     
         5 . The heat-resistant cast steel according to  claim 4 , wherein the heat-resistant cast steel further contains impurities, comprising one or more of Al, P, S, Cu, Ti and Sn. 
     
     
         6 . The heat-resistant cast steel according to  claim 5 , wherein based on the total mass of the heat-resistant cast steel, the corresponding mass percentages of Al, P, S, Cu, Ti and Sn are: ≤0.020 wt % of Al, ≤0.020 wt % of P, ≤0.015 wt % of S, ≤0.15 wt % of Cu, ≤0.020 wt % of Ti and ≤0.020 wt % of Sn. 
     
     
         7 . A preparation method of the heat-resistant cast steel according to  claim 1 , wherein proportioning of raw materials is determined according to proportioning of components in the formula, and the raw materials are melted, refined and poured into a mold; and then, quenching or normalizing is carried out, and finally tempering is carried out. 
     
     
         8 . The preparation method according to  claim 7 , wherein the quenching or normalizing is carried out at a temperature of 1080-1180° C., and then the tempering is carried out at a temperature of 700-780° C., wherein the tempering is carried out one or more times. 
     
     
         9 . Use of the heat-resistant cast steel according  claim 1  in preparation of turbomachinery or as a casting material in the field of steam turbines. 
     
     
         10 . (canceled)