公开(公告)号：EP1712306A4

公开(公告)日：2008-11-12

申请号：EP05709491

申请日：2005-01-31

申请人： SUMITOMO METAL IND

发明人： NAKASHIMA TAKASHI ,  KURODA KOUICHI ,  BEPPU KENICHI

IPC分类号： B21D3/04 ,  B21C1/22 ,  B32B5/14 ,  F16C33/64 ,  F16L9/02

CPC分类号： C21D9/08 ,  B21D3/04 ,  Y10T428/12458

摘要： A cold-finished seamless steel pipe, wherein residual stress produced by correction working after cold-working is controlled to a residual stress F measured by a Crampton method of at least 30 MPa with its variation kept at up to 30 MPa. In addition, as required, the average particle size of globular carbide is specified to thereby reduce deformations in sizes, due to residual strain produced at turning, of the inner and outer surfaces of a steel pipe, and ensure a precision roundness and an excellent machinability at the final working of bearing components. Accordingly, the costs of bearing components can be reduced, and bearing component being high in size precision and less susceptible to deformation at the final working such as turning and heat treating can be provided.

公开(公告)号：EP1820576A4

公开(公告)日：2008-08-27

申请号：EP05805353

申请日：2005-10-28

申请人： SUMITOMO METAL IND

发明人： BEPPU KENICHI

IPC分类号： B21B23/00 ,  B21B17/02 ,  B21B17/14 ,  B21B19/04 ,  B21C1/00

CPC分类号： B21C37/30 ,  B21B17/14 ,  B21B19/04 ,  B21B23/00 ,  B21B45/004 ,  B21C37/06 ,  C21D8/10

摘要： A production method of a seamless steel pipe in which uneven thickness likely occurring in a thin-wall seamless steel pipe can be controlled effectively. A billet soaked for a predetermined time at a predetermined temperature in a heating furnace is subjected to piercing rolling and draw rolling to produce a material pipe which is then soaked for a predetermined time at a predetermined temperature in a reheating furnace and subjected to fixed diameter rolling to produce a seamless steel pipe having a wall thickness of 4 mm or less. Wall thickness of the steel pipe subjected to fixed diameter rolling is set at 4 mm or less, soaking time at a predetermined temperature in the heating furnace is set at billet diameter (mm)×0.14-0.35 min, and soaking time at a predetermined temperature in the reheating furnace is set at bare pipe wall thickness (mm)×3.0-10.0 min.

公开(公告)号：EP1375683A4

公开(公告)日：2006-01-11

申请号：EP02713254

申请日：2002-03-29

申请人： SUMITOMO METAL IND

发明人： KONDO KUNIO ,  YAMAMOTO MIYUKI ,  TAKANO TAKASHI ,  BEPPU KENICHI ,  HIRANO SUSUMU ,  HITOSHIO KEISUKE ,  KURATA HIDETOSHI

IPC分类号： B60R21/268 ,  C21D1/18 ,  C21D8/10 ,  C21D9/08 ,  C22C38/20 ,  C22C38/22 ,  C22C38/26 ,  C22C38/28 ,  C22C38/40 ,  C22C38/42 ,  C22C38/48 ,  C22C38/50 ,  C22C38/58 ,  B60R21/16 ,  C22C38/00

CPC分类号： C22C38/40 ,  B60R21/268 ,  C21D1/18 ,  C21D8/10 ,  C21D9/08 ,  C22C38/20 ,  C22C38/22 ,  C22C38/26 ,  C22C38/28 ,  C22C38/42 ,  C22C38/48 ,  C22C38/50 ,  C22C38/58

摘要： A method for producing a high strength steel tube, which comprises manufacturing a tube by the use of a steel having a chemical composition in mass %: C: 0.05 to 0.20 %; Si: 0.1 to 1.0; Mn: 0.20 to 2.0 %; P: 0.025 % or less; S: 0.010 % or less, Cr: 0.05 to 1.0 %, Al: 0.10 % or less; optionally, at least one of Mo: 0.050 % or less, Ni: 1.5 % or less, Cu: 0.5 % or less, V: 0.2 % or less, Ti: 0.1 % or less, Nb: 0.1 % or less, and B: 0.005 % or less; and also optionally, at least one of Ca: 0.01 % or less, Mg: 0.01 % or less, REM (rare earth element): 0.01 % or less; balance Fe and impurities; and then subjecting the tube to a cold working to form it so as to have predetermined dimensions, and thereafter, heating it to a temperature of the AC1 transformation temperature thereof or higher, followed by quenching, and then, tempering it at a temperature of the AC1 transformation temperature or lower. The steel tube is capable of corresponding to the increase in the pressure of a gas blowing out into an air bag and the reduction in the wall-thickness of an accumulator.