Tata Steel Ijmuiden B.v.

Hoogovens Groep B.v.

Egbert Jansen

Richard Mostert

Theo Arnold Kop

Edward Anton Frederik Span

A dual phase or complex phase steel strip showing no tigerstripes. The steel strip having an ultimate tensile strength Rm classifying for 1000 MPa steel category, includes (in mass percent) C 0.09-0.19%; Mn 1.9-2.6%; Si at most 0.1%; Cr 0.4-0.8%; Mo at most 0.3%; Ni at most 0.4%; Al 0.02-1.3%; and optionally one or more of the following elements: Nb at most 0.08%; P equal to or more than 0.0005%; N equal to or less than 0.015%; Ti equal to or less than 0.1%; V equal to or less than 0.1%; B equal to or less than 0.01%; wherein the sum of Cr, Mo and Ni is at least 0.5%; the balance being Fe and inevitable impurities.

Steel strip having a low Si content

A dual phase or complex phase steel strip showing no tigerstripes. The steel strip includes, in mass percent, the following elements: C 0.08-0.11%; Mn 1.70-2.20%; Si at most 0.1%; Cr 0.40-0.70%; Mo at most 0.3%; Ni at most 1.0%, Al 0.01-1.50%; Nb at most 0.07%; P equal to or more than 0.005%; N equal to or less than 0.015%; Ti equal to or less than 0.1%; V equal to or less than 0.1%; B equal to or less than 0.01%; wherein the sum of Cr, Mo and Ni is at least 0.5%; the balance being Fe and inevitable impurities.

In the wall ironing of a deep-drawn cylindrical body, two ironing ring die regions provide respectively immediately successive first and second thickness reduction phases which take place simultaneously with a relatively small reduction occurring in the first phase and a relatively large reduction occurring in the second phase. Lubricant is applied to the outer surface of the body via inlet between the two die regions. To achieve a high mount of reduction with low applied force, the annular space bounded by the contact regions of the body with said two die regions and the portion of the body located between said two contact regions is fluid-tightly sealed, apart from inlet or inlets for said lubricant, and said space is so shaped and the lubricant is applied through said inlet or inlets at such a pressure that at the second die region hydrodynamic lubrication of the body and die region is achieved.

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Purmerend, Netherlands

Egbert Jansen