Abrasion resistant steel plate having excellent low-temperature toughness and excellent corrosive wear resistance

Abstract

An abrasion resistant steel plate which possesses excellent abrasion resistance, excellent low-temperature toughness and excellent corrosive wear resistance. The abrasion resistant steel plate includes the composition containing by mass %: 0.23% to 0.35% C, 0.05% to 1.00% Si, 0.1% to 2.0% Mn, 0.020% or less P, 0.005% or less S, 0.005% to 0.100% Al, 0.03% to 2.0% Cr, and 0.03% to 1.0% Mo in a state where DI* defined by the following formula (1) is satisfied 45 or more, and further containing remaining Fe and unavoidable impurities as a balance. The steel plate has a structure where an as-quenched martensitic phase forms a main phase and a grain size of prior austenite grains is 30 μm or less, and surface hardness of the steel plate is 450 or more at Brinel hardness HBW10/3000.

1 - 6 . (canceled) 
     
     
         7 . An abrasion resistant steel plate having excellent low temperature toughness and excellent corrosive wear resistance, the steel plate having a composition comprising:
 0.23% to 0.35% C, by mass %;   0.05% to 1.00% Si, by mass %;   0.1% to 2.0% Mn, by mass %;   0.020% or less P, by mass %;   0.005% or less S, by mass %;   0.005% to 0.100% Al, by mass %;   0.03% to 2.0% Cr, by mass %;   0.03% to 1.0% Mo, by mass %, and in an amount where DI* defined by the following formula (1) is 45 or more;
   DI*=33.85×(0.1×C) 0.5 ×(0.7×Si+1)×(3.33×Mn+1)×(0.35×Cu+1)×(0.36×Ni+1)×(2.16×Cr+1)×(3×Mo+1)×(1.75×V+1)  (1)
 
 where C, Si, Mn, Cu, Ni, Cr, Mo and V in the formula (1) refer to the contents (mass %) of respective elements; and 
   remaining Fe and unavoidable impurities as a balance,   wherein the steel plate having a structure where an as-quenched martensitic phase forms a main phase and a grain size of prior austenite grains is in the range of 30 μm or less, and a surface hardness of the steel plate is in the range of 450 or more at Brinel hardness HBW10/3000.   
     
     
         8 . The abrasion resistant steel plate according to  claim 7 , wherein the steel composition further comprises at least one component selected from the group consisting of 0.005% to 0.1% Nb, by mass %, 0.005% to 0.1% Ti, by mass %, and 0.005% to 0.1% V, by mass %. 
     
     
         9 . The abrasion resistant steel plate according to  claim 7 , wherein the steel composition further comprises at least one component selected from the group consisting of 0.005% to 0.2% Sn, by mass %, and 0.005% to 0.2% Sb, by mass %. 
     
     
         10 . The abrasion resistant steel plate according to  claim 8 , wherein the steel composition further comprises at least one component selected from the group consisting of 0.005% to 0.2% Sn, by mass %, and 0.005% to 0.2% Sb, by mass %. 
     
     
         11 . The abrasion resistant steel plate according to  claim 7 , wherein the steel composition further comprises at least one component selected from the group consisting of 0.03% to 1.0% Cu, by mass %, 0.03% to 2.0% Ni, by mass %, and 0.0003% to 0.0030% B, by mass %. 
     
     
         12 . The abrasion resistant steel plate according to  claim 8 , wherein the steel composition further comprises at least one component selected from the group consisting of 0.03% to 1.0% Cu, by mass %, 0.03% to 2.0% Ni, by mass %, and 0.0003% to 0.0030% B, by mass %. 
     
     
         13 . The abrasion resistant steel plate according to  claim 9 , wherein the steel composition further comprises at least one component selected from the group consisting of 0.03% to 1.0% Cu, by mass %, 0.03% to 2.0% Ni, by mass %, and 0.0003% to 0.0030% B, by mass %. 
     
     
         14 . The abrasion resistant steel plate according to  claim 10 , wherein the steel composition further comprises at least one component selected from the group consisting of 0.03% to 1.0% Cu, by mass %, 0.03% to 2.0% Ni, by mass %, and 0.0003% to 0.0030% B, by mass %. 
     
     
         15 . The abrasion resistant steel plate according to  claim 7 , wherein the steel composition further comprises at least one component selected from the group consisting of 0.0005% to 0.008% REM, by mass %, 0.0005% to 0.005% Ca, by mass %, and 0.0005% to 0.005% Mg, by mass %. 
     
     
         16 . The abrasion resistant steel plate according to  claim 8 , wherein the steel composition further comprises at least one component selected from the group consisting of 0.0005% to 0.008% REM, by mass %, 0.0005% to 0.005% Ca, by mass %, and 0.0005% to 0.005% Mg, by mass %. 
     
     
         17 . The abrasion resistant steel plate according to  claim 9 , wherein the steel composition further comprises at least one component selected from the group consisting of 0.0005% to 0.008% REM, by mass %, 0.0005% to 0.005% Ca, by mass %, and 0.0005% to 0.005% Mg, by mass %. 
     
     
         18 . The abrasion resistant steel plate according to  claim 10 , wherein the steel composition further comprises at least one component selected from the group consisting of 0.0005% to 0.008% REM, by mass %, 0.0005% to 0.005% Ca, by mass %, and 0.0005% to 0.005% Mg, by mass %. 
     
     
         19 . The abrasion resistant steel plate according to  claim 11 , wherein the steel composition further comprises at least one component selected from the group consisting of 0.0005% to 0.008% REM, by mass %, 0.0005% to 0.005% Ca, by mass %, and 0.0005% to 0.005% Mg, by mass %. 
     
     
         20 . The abrasion resistant steel plate according to  claim 12 , wherein the steel composition further comprises at least one component selected from the group consisting of 0.0005% to 0.008% REM, by mass %, 0.0005% to 0.005% Ca, by mass %, and 0.0005% to 0.005% Mg, by mass %. 
     
     
         21 . The abrasion resistant steel plate according to  claim 13 , wherein the steel composition further comprises at least one component selected from the group consisting of 0.0005% to 0.008% REM, by mass %, 0.0005% to 0.005% Ca, by mass %, and 0.0005% to 0.005% Mg, by mass %. 
     
     
         22 . The abrasion resistant steel plate according to  claim 14 , wherein the steel composition further comprises at least one component selected from the group consisting of 0.0005% to 0.008% REM, by mass %, 0.0005% to 0.005% Ca, by mass %, and 0.0005% to 0.005% Mg, by mass %. 
     
     
         23 . The abrasion resistant steel plate according to  claim 7 , wherein the content of the as-quenched martensitic phase is in the range of 98% or more in terms of volume fraction. 
     
     
         24 . The abrasion resistant steel plate according to  claim 8 , wherein the content of the as-quenched martensitic phase is in the range of 98% or more in terms of volume fraction. 
     
     
         25 . The abrasion resistant steel plate according to  claim 11 , wherein the content of the as-quenched martensitic phase is in the range of 98% or more in terms of volume fraction. 
     
     
         26 . The abrasion resistant steel plate according to  claim 15 , wherein the content of the as-quenched martensitic phase is in the range of 98% or more in terms of volume fraction. 
     
     
         27 . The abrasion resistant steel plate according to  claim 22 , wherein the content of the as-quenched martensitic phase is in the range of 98% or more in terms of volume fraction.