Stainless steel, slide fastener and buttons suitable for use with needle detector

Abstract

A stainless steel suitable for use with a needle detector, that has a magnetic permeability of 1.005 or less in a magnetic field of 1 kOe, and a magnetization of 550 memu/g or less in a magnetic field of 18 kOe. The steel comprises, in mass %, 0.01 to 0.15% of C, 0.1 to 5% of Si, 1 to 10% of Mn, 8 to 25% of Ni, 14 to 30% of Cr, 0.01 to 0.25% of N, and the remainder Fe and impurities, wherein an Ni equivalent, which is defined as Ni equivalent=Ni+0.6Mn+9.69(C+N)+0.18Cr−0.11Si 2 , has a value of 19 or more, and may further contain at least one selected from among a) 0.5 to 3% of Cu, b) 0.05 to 0.5% of at least one element selected from Nb, W and V, and c) 0.1 to 2% of Mo. The stainless steel enables reliable detection of whether broken needles have got into clothing or the like during sewing, and there can be a slide fastener and buttons that satisfy required properties and can be used with needle detectors due to constituent components thereof being manufactured using the stainless steel.

What is claimed is:  
     
         1 . A stainless steel suitable for use with a needle detector, having a magnetic permeability of 1.005 or less in a magnetic field of 1 kOe, and a magnetization of 550 memu/g or less in a magnetic field of 18 kOe.  
     
     
         2 . The stainless steel suitable for use with a needle detector according to  claim 1 , further exhibiting a needle-detecting performance of 1.2 mm-diameter iron ball or less.  
     
     
         3 . The stainless steel suitable for use with a needle detector according to  claim 1 , further exhibiting a needle-detecting performance of 0.8 mm-diameter iron ball or less.  
     
     
         4 . The stainless steel suitable for use with a needle detector according to  claim 1 , comprising, in mass %, 0.01 to 0.15% of C, 0.1 to 5% of Si, 1 to 10% of Mn, 8 to 25% of Ni, 14 to 30% of Cr, 0.01 to 0.25% of N, and the remainder Fe and impurities, wherein an Ni equivalent, which is defined as Ni equivalent=Ni+0.6Mn+9.69(C+N)+0.18Cr−0.11Si 2 , has a value of 19 or more.  
     
     
         5 . The stainless steel suitable for use with a needle detector according to  claim 4 , further containing, in mass %, at least one additive element selected from the group consisting of a) 0.5 to 3% of Cu, b) 0.05 to 0.5% of at least one element selected from the group consisting of Nb, W and V, and c) 0.1 to 2% of Mo.  
     
     
         6 . The stainless steel suitable for use with a needle detector according to  claim 1 , wherein the needle-detecting performance is maintained after cold rolling at a reduction ratio of 60% has been carried out.  
     
     
         7 . A slide fastener suitable for use with a needle detector, comprising: 
 elements mounted on mutually facing edge parts of a pair of fastener tapes;    stops mounted at both ends of the elements; and    a slider that opens and closes said elements,    wherein at least one member selected from the group consisting of said elements, stops and slider, and constituent components thereof is formed from a stainless steel suitable for use with a needle detector, having a magnetic permeability of 1.005 or less in a magnetic field of 1 kOe, and a magnetization of 550 memu/g or less in a magnetic field of 18 kOe.    
     
     
         8 . The slide fastener suitable for use with a needle detector according to  claim 7 , exhibiting a needle-detecting performance of 1.2 mm-diameter iron ball or less.  
     
     
         9 . The slide fastener suitable for use with a needle detector according to  claim 7 , exhibiting a needle-detecting performance of 0.8 mm-diameter iron ball or less.  
     
     
         10 . The slide fastener suitable for use with a needle detector according to  claim 7 , wherein the slider for slide fastener comprises a slider body, a pull-tab disposed on the slider body, and a latching pawl that is swingable through operation of the pull-tab and is pushed by urging means that applies force toward the slider body side, and at least said urging means is formed from the stainless steel suitable for use with a needle detector.  
     
     
         11 . The slide fastener suitable for use with a needle detector according to  claim 10 , wherein the urging means of the slider is a spring that possesses the latching pawl or a spring that is disposed on the latching pawl.  
     
     
         12 . A button suitable for use with a needle detector, which comprises a front surface member disposed on a front surface of cloth, and a base member disposed on a reverse surface of the cloth, and is attached to the cloth by engaging said front surface member and base member together, 
 wherein at least one member selected from the group consisting of said front surface member and base member, and constituent components thereof is formed from a stainless steel suitable for use with a needle detector, having a magnetic permeability of 1.005 or less in a magnetic field of 1 kOe, and a magnetization of 550 memu/g or less in a magnetic field of 18 kOe.    
     
     
         13 . The button suitable for use with a needle detector according to  claim 12 , exhibiting a needle-detecting performance of 1.2 mm-diameter iron ball or less.  
     
     
         14 . The button suitable for use with a needle detector according to  claim 12 , exhibiting a needle-detecting performance of 0.8 mm-diameter iron ball or less.  
     
     
         15 . A button suitable for use with a needle detector, comprising a pair of buttons consisting of a male button that is fixed to cloth and has on a surface thereof a bulging head part that projects out, and a female button that is fixed to cloth and has a recessed part that separates from and engages with the bulging head part of said male button, wherein at least one member selected from the group consisting of said male button and female button, and constituent components thereof is formed from a stainless steel suitable for use with a needle detector, having a magnetic permeability of 1.005 or less in a magnetic field of 1 kOe, and a magnetization of 550 memu/g or less in a magnetic field of 18 kOe.