Sandvik Intellectual Property Ab

Ab Sandvik Materials Technology

Henrik Häll

Olle Eriksson

A connection tube () for connecting two tubes () of different alloys, wherein the connection tube has a central through-hole extending along a longitudinal axis and comprises a first end portion () of a first alloy, a second end portion () of a second alloy, and a middle portion () which is at least partly double-layered with said second alloy forming an annular inner layer and said first alloy forming an annular outer layer, wherein a metallic bond has been formed between said layers. The inner and outer layers are mechanically interlocked by means of at least one helically extending thread formed in an interface between said layers. The connection tube is manufactured from a base component and an outer component threaded onto the base component to form a work piece, which is hot worked to form a metallic bond.

Connection tube and its method of manufacturing

Herein a tubular element () is disclosed. The tubular element comprises a first tubular portion () comprising a first metal or alloy and a second tubular portion () comprising a second metal or alloy. At least a portion of an interface () between the first and second tubular portions () extends within a fixed diameter range along a longitudinal direction (L) of the tubular element. The second tubular portion () comprises a first end portion () arranged around the first tubular portion (). The second tubular portion () comprises a sealing surface () extending circumferentially around the second tubular portion () at the first end portion ().

Tubular element and assemblies

Method for manufacturing a composite tube having at least one double-layered portion with an annular outer layer of a first alloy and an annular inner layer of a second alloy provides a base component of the second alloy, having a central through-hole and an externally threaded section, provides an outer component of the first alloy, having an internally threaded section configured to engage with the externally threaded section, forms a tubular work piece by mounting the outer component around the base component such that the internally threaded section is in engagement with the externally threaded section, and hot works the work piece so that a metallic bond is formed between the threaded sections while the mechanical interlock is maintained, and so that the work piece is elongated and its outer diameter is reduced, thus forming a composite tube.

Growing community of inventors

Sandviken, Sweden

Henrik Häll