The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
May. 27, 2003

Filed:

Apr. 20, 2000
Applicant:
Inventors:

Massimo Barteri, Rome, IT;

Giorgio Porcu, Rome, IT;

Antonio Mascanzoni, Rome, IT;

Assignee:

Other;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B22D 1/106 ; B22D 1/1124 ;
U.S. Cl.
CPC ...
B22D 1/106 ; B22D 1/1124 ;
Abstract

A process for the production of austenitic stainless steel strips having as case a good weldability, comprising the operations of: solidification in a mold of a continuous casting apparatus with twin counterrotatng rolls, a strip having a thickness comprised between 1 to 5 mm and having the following composition in percent by weight: Cr 17-20; Ni 6-11; c<0.04; n<0.04; s<0.01; Mn<1.5; Si<1.0; Mo 0-3; Al<0.03; and possibly, Ti, Nb, Ta so that: Ti&plus;0.5(Nb&plus;Ta)>6C-3S with proviso that Ti>6S, or NB&plus;Ta>1C with the proviso that TI<6S; being in any case Nb&plus;Ti&plus;Ta<1.0; the remaining part being substantially Fe with a &dgr;-ferrite volume percentage comprised between 4 and 10% calculated with the formula: &dgr;-ferrite&equals;(Creq/Nieq&minus;0.728)&times;500/3 wherein: Creq/Nieq&equals;&lsqb;Cr&plus;Mo&plus;1.5Si&plus;)0.5Nb&plus;0.25Ta&plus;2.5(Al&plus;Ti)&plus;18&rsqb;/&lsqb;Ni&plus;30(C&plus;N)&plus;0.5Mn&plus;36&rsqb;; and, possibly, heating the strip at a temperature between 900 to 1200&deg; C. for a period of time less than 5 minutes. Subject of the invention is also the stainless steel strip obtained with the process and the use thereof for manufactured welded products, i.e. welded tubes.


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