| 摘要 |
PROBLEM TO BE SOLVED: To provide a material for a valve seat of a four-way valve in an air conditioner, which has lower thermal conductance than a conventional copper alloy, can be easily formed into the valve seat, prevents the life of a die from being shortened, and reliably gives the valve seat after having been ground sufficient slidability with respect to a resin. SOLUTION: This material is an austenitic stainless steel sheet which has a composition comprising, by mass%, 0.03% or less C, 1% or less Si, 2% or less Mn, 6-11% Ni, 15-20% Cr, 0.007% or less S, 1-4% Cu, 1% or less Mo, 0.03% or less N, 0-0.03% B, and the balance Fe, while controlling an Md<SB>30</SB>value to -10 or less, which is defined by following expression (1): Md<SB>30</SB>=551-462(C+N)-9.2Si-8.1Mn-29(Ni+Cu)-13.7Cr-18.5Mo; includes crystal grains with a grain size number of 7.5 or less; has a pickled surface with a surface roughness Ra of 0.2μm or more; and has a tensile strength of 520 N/mm<SP>2</SP>or lower. COPYRIGHT: (C)2006,JPO&NCIPI
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