Alloy for high-stress gouging abrasion

1 . A manganese steel alloy having a heat-treated microstructure comprising:

(a) an alloy composition of:

manganese: 12 to 30 wt %;

carbon: 1.0 to 2.0 wt %;

chromium: more than 5 wt % and less than or equal to 7 wt %;

molybdenum: 0.0 to 3.0 wt %; and

iron and impurities: balance;

(b) an austenitic ferrous matrix; and

(c) formed refractory particles dispersed throughout the austenitic ferrous matrix such that ≥10 wt % of the formed refractory particles are located within crystallites of the austenitic ferrous matrix, as opposed to being located at grain boundaries between the crystallites;

wherein the formed refractory particles are chromium rich carbides, and wherein the impurities include one or more of silicon≤1.00 wt %, sulphur≤0.20 wt %, nickel≤0.15 wt %, boron≤0.10 wt %, tungsten≤0.10 wt %, phosphorus≤0.05 wt %, copper≤0.05 wt %, titanium≤0.05 wt % and vanadium≤0.05 wt %.

2 . The manganese steel alloy according to claim 1 , wherein the alloy composition comprises manganese between about 12 wt % and 26 wt %.

3 . The manganese steel alloy according to claim 1 , wherein the alloy composition comprises carbon between about 1.25 wt % and 1.50 wt %.

4 . The manganese steel alloy according to claim 1 , wherein the alloy composition comprises chromium between 5 wt % and 6 wt %.

5 . The manganese steel alloy according to claim 1 , wherein the alloy composition comprises molybdenum between about 0.5 wt % and 2.0 wt %.

6 . The manganese steel alloy according to claim 1 , wherein the alloy composition carbon is selected based on the concentration of manganese to control properties of the microstructure including one or more of:

increasing a rate of formed refractory particles forming throughout the austenitic ferrous matrix, as opposed to being localized at grain boundaries;

decreasing a rate of formed refractory particles forming at grain boundaries of the austenitic ferrous matrix;

increasing a rate of formed refractory particles forming with smooth surfaces;

reducing a rate of formed refractory particles forming with coarse surfaces; and/or

reducing a rate of grain growth within the austenitic ferrous matrix.

7 . The manganese steel alloy according to claim 1 wherein the manganese steel alloy is a cast alloy.

8 . The manganese steel alloy according to claim 7 , wherein the manganese steel alloy is a casting that is heat-treated by solution treatment and quenching.

9 . The manganese steel alloy according to claim 8 , wherein the solution treatment occurs at a temperature between about 1000° C. and 1250° C.

10 . The manganese steel alloy according to claim 7 wherein the quenching is with water.

11 . A method of producing the manganese steel alloy according to claim 1 , comprising the steps of:

(a) forming a melt of a manganese steel comprising heating a composition to a casting temperature, the composition comprising:

manganese: 12 to 30 wt %;

carbon: 1.0 to 2.0 wt %;

chromium: 4.5 to 7.0 wt %;

molybdenum: 0.0 to 3.0 wt %; and

iron and impurities: balance, and

(b) pouring the melt into a mould to form the casting;

(c) allowing the casting to cool to room temperature;

(d) heating the casting to a solution treatment temperature; and

(e) quenching the casting.

12 . The method according to claim 11 , wherein the casting temperature is between about 1350° C. and 1450° C.

13 . The method according to claim 11 , wherein the casting temperature is within 30° C. of a liquidus temperature of the melt of manganese steel.

14 . The method according to claim 11 , wherein the solution treatment temperature is between about 1000° C. and 1250° C.

15 . The method according to claim 11 , wherein the quenching is with water.