Method of detecting fault in piercing-rolling and method of producing seamless pipe or tube

Patent metadata

Field	Value
Publication number	US-9333545-B2
Application number	US-201113882743-A
Country	US
Kind code	B2
Filing date	Nov 1, 2011
Priority date	Nov 2, 2010
Publication date	May 10, 2016
Grant date	May 10, 2016

Abstract

The object is to provide a method of detecting a fault which ensures high-accuracy detection of a fault in piercing-rolling. A piercing-rolling mill ( 10 ) is provided with piercer rolls ( 1 a , 1 b ), a piercer plug ( 3 ), a rolling load sensor ( 4 ), a thrust load sensor ( 5 ), and a control device ( 6 ). The control device ( 6 ) measures a rolling load parameter corresponding to the rolling load of the piercer rolls ( 1 a , 1 b ) and a thrust load parameter corresponding to the thrust load of the piercer plug ( 3 ), and detects a fault in piercing-rolling on the basis of a measured value of the rolling load parameter and a measure value of the thrust load parameter.

First claim

The invention claimed is:

1. A method of detecting a fault in piercing-rolling when a billet is piercing-rolled using piercer rolls and a piercer plug, the method comprising:
piercing-rolling the billet using the piercer rolls and the piercer plug;
measuring a rolling load parameter corresponding to a rolling load of the piercer rolls and a thrust load parameter corresponding to a thrust load of the piercer plug during the piercing-rolling step; and
detecting a fault in piercing-rolling on the basis of the rolling load parameter value and the thrust load parameter value measured in the measuring step,
wherein:
it is judged that a slippage fault in piercing-rolling has occurred in the case where the thrust load parameter value does not exceed a first threshold value of thrust, after the billet is gripped by the piercer rolls, by the time a first prescribed time elapses after the rolling load parameter value exceeds for the first time a first threshold value of rolling; and
it is judged that a head jam fault in piercing-rolling has occurred in the case where the rolling load parameter value does not exceed a second threshold value of rolling, after the billet is gripped by the piercer rolls, by the time a second prescribed time elapses after the thrust load parameter value exceeds for the first time a second threshold value of thrust.

2. A method of producing a seamless pipe or tube by using piercing-rolling, comprising the steps of:
detecting a fault in piercing-rolling by the method according to claim 1 ; and
improving conditions in piercing-rolling when the fault is detected.

Assignees

• Fujiwara Masakazu
• Nippon Steel & Sumitomo Metal Corp

Inventors

• Fujiwara Masakazu

Classifications

• B21B38/00

  Methods or devices for measuring, {detecting or monitoring} specially adapted for metal-rolling mills, e.g. position detection, inspection of the product {(control devices or methods B21B37/00)} · CPC title

• B21B19/04

  Rolling basic material of solid, i.e. non-hollow, structure; Piercing {, e.g. rotary piercing mills} · CPC title

• B21B2265/12

  Rolling load or rolling pressure; roll force · CPC title

• B21C51/00

  Measuring, gauging, indicating, counting, or marking devices specially adapted for use in the production or manipulation of material in accordance with subclasses B21B - B21F · CPC title

• B21B37/78 Primary

  Control of tube rolling · CPC title