Title:
低温における等方じん性が向上した油圧シリンダー用継ぎ目なし精密鋼管およびこれを得る方法
Document Type and Number:
Japanese Patent JP2009541589
Kind Code:
A
Abstract:
Process for manufacturing seamless precision steel tubes with improved isotropic toughness at low temperature for hydraulic cylinders comprising the following steps; —(i) providing a steel having a composition comprising 0.06-0.15% by weight of carbon, 0.30-2.5% by weight of Mn, and 0.10-0.60% by weight of Si, —(ii) hot-rolling the said steel at a temperature higher than Ac3 such as to obtain a seamless steel tube, —(iii) heating the said seamless steel tube at a temperature in the range between Ac1 and Ac3, —(iv) quenching the said heated seamless steel tube, such as to establish a dual (or multi-) phase microstructure in the steel employed, composed of ferrite and martensite and optionally bainite and/or retained austenite, —(v) cold drawing the quenched seamless steel tube such as to provide a seamless precision steel tube of the desired dimensions, —(vi) subjecting the so-obtained seamless precision steel tube to stress relieving treatment to improve its isotropic toughness, and optionally —(vii) straightening the so-obtained seamless precision steel tube with improved toughness.
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Inventors:
Agatsui, Jiyan Mario
Parabicini Bagugliani, Emanuel
Poly, Andrea
Parabicini Bagugliani, Emanuel
Poly, Andrea
Application Number:
JP2009516913A
Publication Date:
November 26, 2009
Filing Date:
June 29, 2006
Export Citation:
Assignee:
Tenaris Connections Actien Gezershyaft
International Classes:
C21D8/10; B21B3/00; B21B23/00; C22C38/00; C22C38/04; C22C38/58
Domestic Patent References:
| JP2001262275A | 2001-09-26 | |||
| JP2001247931A | 2001-09-14 | |||
| JPH0959719A | 1997-03-04 | |||
| JPH10140250A | 1998-05-26 | |||
| JP2002294339A | 2002-10-09 | |||
| JP2003171738A | 2003-06-20 | |||
| JP2009509040A | 2009-03-05 | |||
| JP2005146414A | 2005-06-09 | |||
| JPH0920961A | 1997-01-21 |
Attorney, Agent or Firm:
Patent business corporation Odashima patent office