Method for producing welded tubes from steel

US9221127B2 · kind B2 · utility

Assignee

• EUROPIPE GMBH · DE

Inventors

• Franz Martin Knoop · Vienenburg, DE
• Michael Kaack · Bochum, DE
• Ludwig Oesterlein · Bad Hersfeld, DE

Key dates

• Filing date: Feb 27, 2013
• Grant date: Dec 29, 2015
• Expiry date: Feb 27, 2033

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B23K2101/06
• WIPO field: Machine tools
• WIPO sector: Mechanical engineering

Abstract

In a method for producing welded pipes from steel, in which strips or metal sheets are formed into a pipe provided with a longitudinal or helical slot and the abutting edges of the slotted pipe are welded together, the process parameters for production of the pipes are specified on the basis of previously ascertained material properties and geometry of the strips or metal sheets. Before the forming process, the strip or metal sheet is subjected to an nondestructive, continuous or discontinuous test for inhomogeneities over the length and width, an integral characteristic value for the material property of the strip or metal sheet is formed from the measured values, a measure of the homogeneity of the material properties relating to the length and width of the strip or metal sheet is derived from the variance in the measured values for the various measurement points and, in the event of deviations in the measured values exceeding previously specified limit values, the process parameters are reset and/or the strip or metal sheet is subjected to a homogenisation process prior to the forming process.