Method of making razor blade strip from austenitic steel

Claim 1

A method of manufacturing razor blade strip, to a state at which it is ready for cutting-edge formation, from an alloy whose composition is ______________________________________ Ni% 15 to 25 Cr% 3 to 8 Ti% 2 to 5 Al% 1 to 5 ______________________________________ with the total of titanium plus aluminium being less than 9%, the balance being iron and impurities, the level of impurities being such that: ______________________________________ C% less than 0.02 Mn% less than 0.2 Si% less than 0.2 N% less than 0.02 P% less than 0.02 S% less than 0.02 ______________________________________ comprising the steps of hot forging the alloy to bar, rolling the bar to strip, without prior cooling, maintaining the strip at elevated temperature to austenitise the structure, quenching the strip, descaling the strip, reducing the strip to final thickness, and finally subjecting the strip to hardening at a temperature of between 500° and 600° C. for not more than ten minutes.

Claim 2

A method of manufacturing razor blade strip, to a state at which it is ready for cutting-edge formation, from an alloy whose composition is ______________________________________ Ni% 15 to 25 Cr% 3 to 8 Ti% 2 to 5 Al% 1 to 5 ______________________________________ with the total of titanium plus aluminium being less than 9%, the balance being iron and impurities, the level of impurities being such that: ______________________________________ C% less than 0.02 Mn% less than 0.2 Si% less than 0.2 N% less than 0.02 P% less than 0.02 S% less than 0.02 ______________________________________ comprising the steps of hot forging the alloy to bar, rolling the bar to strip, without prior cooling, maintaining the strip at elevated temperature to austenitise the structure, quenching the strip, descaling the strip, reducing the strip to final thickness, and finally subjecting the strip to hardening at a temperature of between 500° and 600° C. for not more than ten minutes.

Claim 3

A method of manufacturing razor blade strip, to a state at which it is ready for cutting-edge formation, from an alloy whose composition is: ______________________________________ Ni % 20 Cr % 4 Ti % 4 Al % 3 ______________________________________ the balance being iron and impurities, the level of impurities being such that: ______________________________________ C % less than 0.005 Mn % less than 0.05 Si % less than 0.05 N % less than 0.003 P % less than 0.005 S % less than 0.005 ______________________________________ comprising the steps of hot forging the alloy to bar, rolling the bar to rod, without prior cooling, maintaining the rod at elevated temperature to austenitise the structure, quenching the rod, descaling the rod, drawing down the rod to wire, rolling the wire to strip, and finally subjecting the strip to hardening at a temperature of between 500° and 600° C. for less than one minute.

Claim 4

A method of manufacturing razor blade strip, to a state at which it is ready for cutting-edge formation, from an alloy whose composition is: ______________________________________ Ni % 20 Cr % 4 Ti % 4 Al % 3 ______________________________________ the balance being iron and impurities, the level of impurities being such that: ______________________________________ C % less than 0.005 Mn % less than 0.05 Si % less than 0.05 N % less than 0.003 P % less than 0.005 S % less than 0.005 ______________________________________ comprising the steps of hot forging the alloy to bar, rolling the bar to rod, without prior cooling, maintaining the rod at elevated temperature to austenitise the structure, quenching the rod, descaling the rod, drawing down the rod to wire, rolling the wire to strip, and finally subjecting the strip to hardening at a temperature of between 500° and 600° C. for less than one minute.

Claim 10

A method of manufacturing razor blade strip, to a state at which it is ready for cutting-edge formation, from an alloy whose composition is: ______________________________________ Ni % 20 Cr % 4 Ti % 4 Al % 3 ______________________________________ the balance being iron and impurities, the level of impurities being such that ______________________________________ C % less than 0.005 Mn % less than 0.05 Si % less than 0.05 N % less than 0.003 P % less than 0.005 S % less than 0.005 ______________________________________ comprising the steps of hot forging the alloy to bar at a temperature in the region of 1200° C., rolling the bar to strip, without prior cooling, maintaining the strip at elevated temperature to austenitise the structure, quenching the strip, descaling the strip, reducing the strip to final thickness whilst subjecting the strip during the reduction process to intermediate anneals at temperatures in the range 1050° to 1250° C., and finally subjecting the strip to hardening at a temperature of between 500° and 600° C. for less than one minute.

Claim 11

A method of manufacturing razor blade strip, to a state at which it is ready for cutting-edge formation, from an alloy whose composition is: ______________________________________ Ni % 20 Cr % 4 Ti % 4 Al % 3 ______________________________________ the balance being iron and impurities, the level of impurities being such that ______________________________________ C % less than 0.005 Mn % less than 0.05 Si % less than 0.05 N % less than 0.003 P % less than 0.005 S % less than 0.005 ______________________________________ comprising the steps of hot forging the alloy to bar at a temperature in the region of 1200° C., rolling the bar to strip, without prior cooling, maintaining the strip at elevated temperature to austenitise the structure, quenching the strip, descaling the strip, reducing the strip to final thickness whilst subjecting the strip during the reduction process to intermediate anneals at temperatures in the range 1050° to 1250° C., and finally subjecting the strip to hardening at a temperature of between 500° and 600° C. for less than one minute.

Claim 12

A method of manufacturing razor blade strip, to a state at which it is ready for cutting-edge formation, from an alloy whose composition is: ______________________________________ Ni % 17 to 22 Cr % 3.5 to 5 Ti % 3 to 4.5 Al % 2 to 4 ______________________________________ the total of nickel plus chromium being from 22 to 26%, the balance being iron and impurities, the level of impurities being such that: ______________________________________ C % less than 0.01 Mn % less than 0.1 Si % less than 0.1 N % less than 0.01 P % less than 0.01 S % less than 0.01 ______________________________________ comprising the steps of hot forging the alloy to bar, rolling the bar to rod, without prior cooling, maintaining the rod at elevated temperature to austenitise the structure, quenching the rod, descaling the rod, drawing down the rod to wire, rolling the wire to strip, and finally subjecting the strip to hardening at a temperature of between 500° and 600° C. for less than one minute.

Claim 13

A method of manufacturing razor blade strip, to a state at which it is ready for cutting-edge formation, from an alloy whose composition is: ______________________________________ Ni % 17 to 22 Cr % 3.5 to 5 Ti % 3 to 4.5 Al % 2 to 4 ______________________________________ the total of nickel plus chromium being from 22 to 26%, the balance being iron and impurities, the level of impurities being such that: ______________________________________ C % less than 0.01 Mn % less than 0.1 Si % less than 0.1 N % less than 0.01 P % less than 0.01 S % less than 0.01 ______________________________________ comprising the steps of hot forging the alloy to bar, rolling the bar to rod, without prior cooling, maintaining the rod at elevated temperature to austenitise the structure, quenching the rod, descaling the rod, drawing down the rod to wire, rolling the wire to strip, and finally subjecting the strip to hardening at a temperature of between 500° and 600° C. for less than one minute.