Manufacturing method and steel for heavy munition casings

Abstract

A manufacturing method for a heavy munition casing is provided, in which steel is rolled as a rough sheet or is forged as a slab depending on the desired casing size. Steel plates ( 2 ) produced in this way have a thickness that is somewhat greater than the manufacturing diameter of the munition casing ( 5 ). The steel used for this purpose has longitudinally oriented manganese sulfides ( 3 ), which are also shaped in the lateral direction, in addition to main shaping in the longitudinal direction, by shaping to form the shaped steel plate ( 2 ), and assume a longitudinally extending plate-shape as well. The initial material for the casing ( 5 ) is taken from an approximately rectangular steel plate ( 2 ), transversely with respect to the deformation direction. The quadrilateral piece obtained in this way is then turned to be round and is mechanically processed to form the shape of the casing ( 5 ).

1 . A manufacturing method for the production of a steel or of steel plates, wherein the method comprises the following steps:
 (a) rolling steel plates as a rough sheet or forging steel plates as a slab, depending on a desired size; and   (b) through shaping of the rough sheet or through producing a shaped plate, wherein manganese sulfides situated in the shaped plate, in addition to the main shaping in a longitudinal direction, are also deformed in a transverse direction and assume a longitudinally extended shape so that the manganese sulfides form in a plate-shape.   
     
     
         2 . A manufacturing method according to  claim 1 , wherein the shaped plate is quenched and tempered to the desired strength preferably directly after shaping. 
     
     
         3 . A manufacturing method according to  claim 2 , wherein the desired strength is in the range of 900-1200 N/mm 2 . 
     
     
         4 . Steel for use for the manufacture of a heavy munition casing according to  claim 1 , wherein the steel comprises:
 (a) 0.30 to 0.60% carbon, by weight;   (b) a maximum of 1.0% silicon, by weight;   (c) a maximum of 2.0% manganese, by weight:   (d) a maximum of 0.05% phosphorus, by weight;   (e) 0.03 to 0.25% sulfur, by weight:   (f) a maximum of 2.0% chromium, by weight;   (g) a maximum of 0.5% molybdenum, by weight:   (h) as well as a remainder of iron and unavoidable impurities.   
     
     
         5 . Steel according to  claim 4 , comprising:
 (a) 0.35 to 0.45% carbon, by weight;   (b) 0.30 to 0.60% silicon, by weight;   (c) 1.40 to 1.60% manganese, by weight:   (d) a maximum of 0.035% phosphorus, by weight;   (e) 0.05 to 0.10% sulfur, by weight:   (f) 1.80 to 2.10% chromium, by weight;   (g) 0.15 to 0.25% molybdenum, by weight:   (h) as well as a remainder of iron and unavoidable impurities.   
     
     
         6 . A munition casing, produced according to the manufacturing method according to  claim 1 , wherein the munition casing includes:
 (a) steel comprising
 i. 0.30 to 0.60% carbon, by weight; 
 ii. a maximum of 1.0% silicon, by weight; 
 iii. a maximum of 2.0% manganese, by weight; 
 iv. a maximum of 0.05% phosphorus, by weight; 
 v. 0.03 to 0.25% sulfur, by weight: 
 vi. a maximum of 2.0% chromium, by weight; 
 vii. a maximum of 0.5% molybdenum, by weight; 
 viii. as well as a remainder of iron and unavoidable impurities: 
   (b) a casing wall made by taking an initial piece from a plate made of the steel, wherein the initial piece is taken transverse to a deformation direction through sawing, and wherein the casing wall defines an interior space; and   (c) plate-shaped manganese sulfides situated radially in high density in the steel in a cross section of the casing wall, wherein the manganese sulfides embrittle the steel and are arranged radially in the casing wall so that when the interior space is under a bursting pressure, local fractures are triggered in the casing wall.   
     
     
         7 . A munition casing according to  claim 6 , wherein the thickness of the plate is somewhat greater than a manufacturing diameter of the munition casing, wherein a width of the plate corresponds to at least a length of the munition casing. 
     
     
         8 . Steel according to  claim 4 , wherein the steel has a strength in the range of 900-1200 N/mm 2 . 
     
     
         9 . Steel for use for the manufacture of a heavy munition casing according to  claim 1 , wherein the steel consists essentially of:
 (a) 0.35 to 0.45% carbon, by weight;   (b) 0.30 to 0.60% silicon, by weight;   (c) 1.40 to 1.60% manganese, by weight;   (d) a maximum of 0.035% phosphorus, by weight;   (e) 0.05 to 0.10% sulfur, by weight;   (f) 1.80 to 2.10% chromium, by weight;   (g) 0.15 to 0.25% molybdenum, by weight;   (h) as well as a remainder of iron and unavoidable impurities, wherein the steel has a strength in the range of 900-1200 N/mm 2 .   
     
     
         10 . Steel for use for the manufacture of a heavy munition casing according to  claim 1 , wherein the steel consists of:
 (a) 0.35 to 0.45% carbon, by weight;   (b) 0.30 to 0.60% silicon, by weight;   (c) 1.40 to 1.60% manganese, by weight;   (d) a maximum of 0.035% phosphorus, by weight;   (e) 0.05 to 0.10% sulfur, by weight;   (f) 1.80 to 2.10% chromium, by weight;   (g) 0.15 to 0.25% molybdenum, by weight;   (h) as well as a remainder of iron and unavoidable impurities.   
     
     
         11 . Steel according to  claim 10 , wherein the steel has a strength in the range of 900-1200 N/mm 2 . 
     
     
         12 . Steel according to  claim 4 , wherein the steel includes plate-shaped manganese sulfides. 
     
     
         13 . Steel according to  claim 9 , wherein the steel includes a phase comprising plate-shaped manganese sulfides. 
     
     
         14 . Steel according to  claim 10 , wherein the steel includes a phase comprising plate-shaped manganese sulfides formed by the manganese and the sulfur. 
     
     
         15 . A munition casing according to  claim 6 , wherein the thickness of the plate is somewhat greater than a manufacturing diameter of the munition casing, wherein a width of the plate corresponds to at least a multiple of a length of the munition casing.