公开(公告)号：US20170143455A1

公开(公告)日：2017-05-25

申请号：US15300003

申请日：2015-03-19

Applicant: HITACHI METALS, LTD.

Inventor： Yukyo TAKADA ,  Masatoshi TAKAHASHI ,  Akira KIKUCHI

IPC: A61C8/00 ,  C22C38/00 ,  B23K31/02 ,  C21D6/00 ,  C23C8/26 ,  C22C38/44 ,  C21D9/52

CPC classification number: A61C8/0081 ,  A61C8/00 ,  A61C13/235 ,  B23K31/02 ,  B23K2103/05 ,  C21D6/002 ,  C21D6/004 ,  C21D8/12 ,  C21D9/525 ,  C21D2211/005 ,  C21D2251/04 ,  C22C38/00 ,  C22C38/001 ,  C22C38/40 ,  C22C38/44 ,  C23C8/02 ,  C23C8/26 ,  C23C8/80

Abstract: A magnet assembly for a dental magnetic attachment comprising a cup-shaped yoke of substantially Ni-free ferritic stainless steel, a permanent magnet received in a recess of the cup-shaped yoke, a seal member sealing an opening of the cup-shaped yoke, and an abutment-welded portion of the seal member and the cup-shaped yoke; the seal member comprising a center portion of substantially Ni-free ferritic stainless steel; an intermediate portion of substantially Ni-free austenitic stainless steel having a nitrogen content of 0.5-2.0% by mass, and a peripheral portion made of substantially Ni-free ferritic stainless steel having a nitrogen content of 1.3% or less by mass, smaller than in the intermediate portion.