Steel for producing parts for railway, railway crossings and switches and method for producing said parts

Abstract

Wrought steel for producing parts for railway, railway crossings or railway switches including (in weight percent): 0.01-0.15% carbon; at most 0.5% silicon; 10-15% manganese; at least 0.6 to 3.95% molybdenum; optionally one or more of the following elements: i. 0.05 to 0.2% nickel, and/or ii. 0.05 to 0.2% cobalt, and/or iii. 0.02 to 0.30% Cr, and/or iv. 0.05 to 0.2% copper, v. at most 5 ppm H, vi. at most 0.20% V, vii. at most 0.10% Nb; viii. at most 0.20% Ti and/or Zr, ix. at most 50 ppm B; x. at most 250 ppm N; xi. at most 0.2% Al, xii. at most 0.08% S, xiii. at most 0.08% P; xiv. at most 1.5% W; and balance iron and inevitable impurities; and a method of producing the wrought steel and its use.

1 . A wrought steel for producing parts for railway, railway crossings or railway switches comprising (in weight percent):
 0.01-0.15% carbon;   at most 0.5% silicon;   10-15% manganese;   at least 0.6 to 3.95% molybdenum;   optionally one or more of the following elements
 i. 0.05 to 0.2% nickel and/or 
 ii. 0.05 to 0.2% cobalt and/or 
 iii. 0.02 to 0.30% Cr and/or 
 iv. 0.05 to 0.2% copper; 
 v. at most 5 ppm H; 
 vi. at most 0.20% V; 
 vii. at most 0.10% Nb; 
 viii. at most 0.20% Ti and/or Zr; 
 ix. at most 50 ppm B; 
 x. at most 250 ppm N; 
 xi. at most 0.2% Al; 
 xii. at most 0.08% S; 
 xiii. at most 0.08% P; 
 xiv. at most 1.5% W; 
   and balance iron and inevitable impurities.   
     
     
         2 . The steel according to  claim 1 , comprising at most 0.12% C and/or at least 11% of Mn, and/or at most 2.95% Mo. 
     
     
         3 . The steel according to  claim 1 , comprising at most 0.02% S and at most 0.02% P. 
     
     
         4 . The steel according to  claim 1 , comprising at most 0.10% C. 
     
     
         5 . The steel according to  claim 1 , comprising at most 14% Mn. 
     
     
         6 . The steel according to  claim 1 , comprising at least 0.10% Si. 
     
     
         7 . The steel according to  claim 1 , comprising at least 15% in volume of retained austenite in its as-hot rolled state. 
     
     
         8 . The steel according to  claim 1 , comprising
 at least 1% Mo, and/or   at most 2.45% Mo.   
     
     
         9 . The steel according to  claim 1 , comprising at least 0.02% C. 
     
     
         10 . The steel according to  claim 1 , wherein the steel comprises between 0.05 and 0.1% vanadium and/or between 0.025 and 0.075% Nb. 
     
     
         11 . A method for producing a wrought steel part for railway, railway crossings or railway switches comprising the steps of:
 providing a starting material having a composition according to  claim 1 ;   providing the starting material at an appropriate temperature for hot rolling the starting material into a plate or rail, and hot rolling the starting material into a hot rolled plate; wherein
 i. the hot-rolled plate has a thickness sufficient for machining the part out of the hot-rolled plate, or 
 ii. wherein the rail has the desired rail profile for
 a. machining into a part for railway crossings and switches such as a switchblade or 
 b. for use as a rail; 
 
 iii. allowing the plate or rail to cool after the last hot deformation to achieve the desired mechanical properties; 
   machining the part for railway crossings or railway switches from the hot-rolled and cooled plate or rail.   
     
     
         12 . The method according to  claim 11 , further comprising the additional step of welding one or more rails to the wrought steel part. 
     
     
         13 . The method according to  claim 11 , wherein the wrought steel part for railway, railway crossings or railway switches is a frog or a double frog or a switchblade. 
     
     
         14 . A railway, railway crossing or railway switch comprising the wrought steel part produced according to  claim 11 . 
     
     
         15 . The railway, railway crossing or railway switch according to  claim 14 , wherein the steel part has been, at least partly, weld restored by an in-situ weld repair procedure. 
     
     
         16 . The method according to  claim 11 , wherein the starting material is a bloom or ingot. 
     
     
         17 . A railway, railway crossing or railway switch comprising a wrought steel part having a composition according to  claim 1 . 
     
     
         18 . The railway, railway crossing or railway switch according to  claim 17 , wherein the steel part has been, at least partly, weld restored by an in-situ weld repair procedure. 
     
     
         19 . The railway, railway crossing or railway switch according to  claim 17 , wherein the wrought steel part is a frog or a double frog or a switchblade. 
     
     
         20 . The railway, railway crossing or railway switch according to  claim 17 , the wrought steel part comprising at least 15% in volume of retained austenite during its use as part of the railway, railway crossing or railway switch. 
     
     
         21 . The steel according to  claim 1 , comprising
 at least 1.25 Mo and/or   at most 1.90% Mo.