Data storage device

Abstract

Provided are novel data storage devices, such as hard disk apparatuses. The devices include a clean chamber accommodating a component formed from a free cutting stainless steel. The free cutting stainless steel has a sulfur (S) content of not less than 0.25 percent by mass and a manganese-to-sulfur content ratio (Mn/S) of not greater than 1.8. The free cutting stainless steel has been subjected to: (1) an acid cleaning; (2) to a passivation treatment; (3) to a degreasing treatment and to a subsequent rust-removing, descaling chemical treatment; or (5) to a degreasing treatment and to a subsequent chromate treatment.

What is claimed is:  
     
         1 . A hard disk apparatus, comprising: 
 a clean chamber accommodating a hard disk driven by a spindle motor, and a magnetic head capable of making access to said hard disk, wherein a free cutting stainless steel is used as the material of a member accommodated in said clean chamber,    said free cutting stainless steel having a sulfur (S) content of not less than 0.25 percent by mass and a manganese-to-sulfur content ratio (Mn/S) of not greater than 1.8,    said free cutting stainless steel having been subjected to an acid cleaning.    
     
     
         2 . The hard disk apparatus according to    claim 1   , wherein the acid cleaning is conducted with a treating solution which is an aqueous solution of an acid effective to remove contaminants, rust and scale remaining on the surface of the free cutting stainless steel.  
     
     
         3 . The hard disk apparatus according to    claim 1   , wherein the acid cleaning is conducted with a treating solution comprising nitric acid.  
     
     
         4 . The hard disk apparatus according to    claim 1   , wherein following the acid cleaning, the free cutting stainless steel is subjected to a neutralizing treatment and a chromate treatment.  
     
     
         5 . The hard disk apparatus according to    claim 1   , wherein said component is a rotor hub of said spindle motor.  
     
     
         6 . A hard disk apparatus, comprising: 
 a clean chamber accommodating a hard disk driven by a spindle motor, and a magnetic head capable of making access to said hard disk, wherein a free cutting stainless steel is used as the material of a member accommodated in said clean chamber,    said free cutting stainless steel having a sulfur (S) content of not less than 0.25 percent by mass and a manganese-to-sulfur content ratio (Mn/S) of not greater than 1.8,    said free cutting stainless steel having been subjected to a passivation treatment.    
     
     
         7 . The hard disk apparatus according to    claim 6   , wherein the passivation treatment is conducted with a nitric acid treating solution.  
     
     
         8 . The hard disk apparatus according to    claim 6   , wherein the passivation treatment is conducted with a treating solution which is a mixture of nitric acid and sodium bichromate, and wherein an alkali neutralizing treatment is conducted after the passivation treatment.  
     
     
         9 . The hard disk apparatus according to    claim 8   , wherein a chromate treatment is conducted after the alkali neutralizing treatment.  
     
     
         10 . The hard disk apparatus according to    claim 6   , wherein said free cutting stainless steel is heat-treated at a temperature of from about 100° C. to about 200° C. after the passivation treatment.  
     
     
         11 . The hard disk apparatus according to    claim 6   , wherein said free cutting stainless steel is heat-treated at a temperature of from about 70° C. to about 150° C. in a vacuum or a substantially vacuum atmosphere after the passivation treatment.  
     
     
         12 . The hard disk apparatus according to    claim 6   , wherein said member is a rotor hub of said spindle motor.  
     
     
         13 . A hard disk apparatus, comprising: 
 a clean chamber accommodating a hard disk driven by a spindle motor, and a magnetic head capable of making access to said hard disk, wherein a free cutting stainless steel is used as the material of a member accommodated in said clean chamber,    said free cutting stainless steel having a sulfur (S) content of not less than 0.25 percent by mass and a manganese-to-sulfur content ratio (Mn/S) of not greater than 1.8,    said free cutting stainless steel having been subjected to a degreasing treatment and to a subsequent rust-removing, descaling chemical treatment.    
     
     
         14 . The hard disk apparatus according to    claim 13   , wherein the rust-removing, descaling chemical treatment is conducted with a treating solution which is an aqueous solution of an acid having an acid concentration of 3 percent by volume or less.  
     
     
         15 . The hard disk apparatus according to    claim 13   , wherein the rust-removing, descaling chemical treatment comprises an alkali electrolytic cleaning.  
     
     
         16 . The hard disk apparatus according to claims  13 , wherein following the rust-removing, descaling chemical treatment said free cutting stainless steel is subjected to a chromate treatment.  
     
     
         17 . The hard disk apparatus according to    claim 13   , wherein said member is a rotor hub of said spindle motor.  
     
     
         18 . A hard disk apparatus, comprising: 
 a clean chamber accommodating a hard disk driven by a spindle motor, and a magnetic head capable of making access to said hard disk, wherein a free cutting stainless steel is used as the material of a member accommodated in said clean chamber,    said free cutting stainless steel having a sulfur (S) content of not less than 0.25 percent by mass and a manganese-to-sulfur content ratio (Mn/S) of not greater than 1.8,    said free cutting stainless steel having been subjected to a degreasing treatment and to a subsequent chromate treatment.    
     
     
         19 . The hard disk apparatus according to    claim 18   , wherein prior to the degreasing treatment, the free cutting stainless steel is subjected to a mechanical descaling treatment.  
     
     
         20 . The hard disk apparatus according to    claim 18   , wherein said member is a rotor hub of said spindle motor.  
     
     
         21 . A data storage device, comprising a clean chamber accommodating a component, said component being formed from a free cutting stainless steel, said free cutting stainless steel having a sulfur (S) content of not less than 0.25 percent by mass and a manganese-to-sulfur content ratio (Mn/S) of not greater than 1.8, said free cutting stainless steel having been subjected to an acid cleaning.  
     
     
         22 . The data storage device according to    claim 21   , wherein the acid cleaning is conducted with a treating solution which is an aqueous solution of an acid effective to remove contaminants, rust and scale remaining on the surface of the free cutting stainless steel.  
     
     
         23 . The data storage device according to    claim 21   , wherein the acid cleaning is conducted with a treating solution comprising nitric acid.  
     
     
         24 . The data storage device according to    claim 21   , wherein following the acid cleaning, the free cutting stainless steel is subjected to a neutralizing treatment and a chromate treatment.  
     
     
         25 . The data storage device according to    claim 21   , wherein a spindle motor is accommodated in the clean chamber for driving one or more data storage media, and a rotor hub of said spindle motor constitutes a part of said component.  
     
     
         26 . A data storage device, comprising a clean chamber accommodating a component, said component being formed from a free cutting stainless steel, said free cutting stainless steel having a sulfur (S) content of not less than 0.25 percent by mass and a manganese-to-sulfur content ratio (Mn/S) of not greater than 1.8, said free cutting stainless steel having been subjected to a passivation treatment.  
     
     
         27 . The data storage device according to    claim 26   , wherein the passivation treatment is conducted with a nitric acid treating solution.  
     
     
         28 . The data storage device according to    claim 26   , wherein the passivation treatment is conducted with a treating solution which is a mixture of nitric acid and sodium bichromate, and wherein an alkali neutralizing treatment is conducted after the passivation treatment.  
     
     
         29 . The data storage device according to    claim 27   , wherein a chromate treatment is conducted after the alkali neutralizing treatment.  
     
     
         30 . The data storage device according to    claim 26   , wherein said free cutting stainless steel is heat-treated at a temperature of from about 100° C. to about 200° C. after the passivation treatment.  
     
     
         31 . The data storage device according to    claim 26   , wherein said free cutting stainless steel is heat-treated at a temperature of from about 70° C. to about 150° C. in a vacuum or a substantially vacuum atmosphere after the passivation treatment.  
     
     
         32 . The data storage device according to    claim 26   , wherein a spindle motor is accommodated in the clean chamber for driving one or more data storage media, and a rotor hub of said spindle motor constitutes a part of said component.  
     
     
         33 . A data storage device, comprising a clean chamber accommodating a component, said component being formed from a free cutting stainless steel, said free cutting stainless steel having a sulfur (S) content of not less than 0.25 percent by mass and a manganese-to-sulfur content ratio (Mn/S) of not greater than 1.8, said free cutting stainless steel having been subjected to a degreasing treatment and to a subsequent rust-removing, descaling chemical treatment.  
     
     
         34 . The data storage device according to    claim 33   , wherein the rust-removing, descaling chemical treatment is conducted with a treating solution which is an aqueous solution of an acid having an acid concentration of 3 percent by volume or less.  
     
     
         35 . The data storage device according to    claim 33   , wherein the rust-removing, descaling chemical treatment comprises an alkali electrolytic cleaning.  
     
     
         36 . The data storage device according to    claim 33   , wherein following the rust-removing, descaling chemical treatment, said free cutting stainless steel is subjected to a chromate treatment.  
     
     
         37 . The data storage device according to    claim 33   , wherein a spindle motor is accommodated in the clean chamber for driving one or more data storage media, and a rotor hub of said spindle motor constitutes a part of said component.  
     
     
         38 . A data storage device, comprising a clean chamber accommodating a component, said component being formed from a free cutting stainless steel, said free cutting stainless steel having a sulfur (S) content of not less than 0.25 percent by mass and a manganese-to-sulfur content ratio (Mn/S) of not greater than 1.8, said free cutting stainless steel having been subjected to a degreasing treatment and to a subsequent chromate treatment.  
     
     
         39 . The data storage device according to    claim 38   , wherein prior to the degreasing treatment, the free cutting stainless steel is subjected to a mechanical descaling treatment.  
     
     
         40 . The data storage device according to    claim 38   , wherein a spindle motor is accommodated in the clean chamber for driving one or more data storage media, and a rotor hub of said spindle motor constitutes a part of said component.