Patent ID: 9487841
Filing Date: 2016-11-08
CPC Classification: C21D,C22C

Claim Text:
1. A method of producing a linepipe which includes the steps of: (a) centre-slitting a linepipe steel strip to form a length of slit steel strip, wherein the linepipe steel has the following composition, in wt. %: (b) forming the length of slit steel strip into a pipe and electric resistance welding lengthwise extending side edges together to form the linepipe, wherein the linepipe has a weld line toughness of at least 80 J, as measured in Charpy V Impact tests at 0° C., and wherein the microstructure of the linepipe is essentially unchanged by the pipe forming step (b) and is the same as that of the linepipe steel strip before the centre-slitting step (a).