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Electromagnetic stainless steel

Magnetic core material, which is essential in electromagnetic actuators, is required to have various different properties such as corrosion resistance, magnetic property, electrical resistance, and workability depending on the usage or performance. We have broadened our lineup of soft-magnetic stainless steels to meet varying demands ever since we introduced the world’s first soft-magnetic stainless steel K-M31 over 50 years ago.

Features

Compared with pure iron magnetic materials:

  1. High corrosion-resistance
  2. High electrical resistance

To meet processing methods:

  1. Free-cutting types
  2. Cold fogeabie types

Compared to general ferrite stainless steel:

  1. Excellent magnetic properties

[Usage]

Fuel injectors, solenoid valve cores,
Magnetic sensors, magnetometric sensors, semiconductor valve stems,
massflow controller cores

Description of materials

[Composition]

  • K-M31　13Cr-2Si
  • K-M35FL　13Cr-0.7Si-0.2Al-0.2Pb
  • K-M62F　13Cr-0.8Al-Mo,Ti,Pb
  • K-M41F　17Cr-1Si-Mo,S,Ti
  • K-M38　18Cr-2Si-2Mo
  • K-M45　20Cr-2Si-2Mo
  • K-M60　13Cr-0.2Al-1Mo

[Standard heat treatment condition]

  • K-M31、K-M35FL、K-M62F、K-M60　950℃×3hr-furnace cooling
  • K-M38、K-M41F　850℃×3hr-furnace cooling
  • K-M45　1000℃×3hr-rapid cooling

Characteristics

[Soft-magnetic properties, pitting potential]

Steel name Soft-magnetic properties Corrosion resistance
Max.
permeability
μｍ		 Coercivity
Hc
A/ｍ		 Magnetic flux density
B2000
T		 Volume electrical resistivity
ρ
μΩcm		 Pitting potential
mV
K-M31 2500 105 1.25 92 -10
K-M35FL 4500 75 1.30 72 -130
K-M62F 4800 84 1.34 76 20
K-M41F 1430 203 1.21 76 200
K-M38 3000 80 1.15 85 350
K-M45 4000 60 1.10 109 750
K-M60 3500 85 1.35 65 0
scrollable

[Mechanical properties, hardness]

Steel name Mechanical properties Hardness
Proof strength
YS
MPa		 Tensile strength
TS
MPa		 Elongation
EL
%		 Reduction of area
ROA
％		 HRB
K-M31 400 570 43 73 88
K-M35FL 245 370 47 74 70
K-M62F 234 397 47 78 70
K-M41F 343 491 37 66 82
K-M38 450 590 36 70 90
K-M45 590 680 32 70 95
K-M60 225 370 46 83 70
scrollable

The characteristics above are those after standard heat treatment.

Other

[Lead-free of free-cutting steel]

Lead-free is possible by dispersing TICS in steels.
Refer to Pb Free TICS Free-Cutting Soft-magnetic Stainless Steel.

[SEMI certified materials]

K-M38 and K-M45 are the only alternatives to ultrahigh purity grade materials among ferrite stainless steels in SEMI F105-0914 "Guide to Metallic Material Compatibility in Gas Supply Systems".

※SEMI＝Semiconductor Equipment and Material International