# US 2014/0197825 A1 · Arrangement For Crack Detection In Metallic Materials In A Metal Making Process > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0197825 A1 - Document ID: US20140197825A1 - Status: Published application - Kind: A1 - Application number: 14/202,988 - Filed: 2014-03-10 - Published: 2014-07-17 - Earliest claimed: 2011-09-29 - Assignees: ABB Technology AG - Inventors: Lennart Thegel; Sten Linder - Web page: https://patentgrep.com/patent/US20140197825A1 ## CPC - G01N 27/82: for investigating the presence of flaws - B21B 38/00: 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)} - G01N 27/9026: {by moving the material} - G01L 3/105: {involving inductive means (G01L3/102, G01L3/104 take precedence)} - G01R 33/18: Measuring magnetostrictive properties - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - B21B: ROLLING OF METAL (auxiliary operations used in connection with metal-working operations covered in B21, see B21C; bending by rolling B21D; manufacture of particular objects, e.g. screws, wheels, rings, barrels, balls, by rolling B21H; pressure welding by means of a rolling mill B23K20/04) - G01L: MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE (weighing G01G) - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract An arrangement for a metal making process for detecting cracks along a strip of a metallic material moving in relation to the arrangement. The arrangement includes a coil arrangement fixedly arranged during crack inspection, having: a first winding portion extending in a first direction for inducing a first current in the first direction; a second winding portion extending in a second direction for inducing a second current in the second direction, the first direction and the second direction intersecting each other; a first receiver coil arranged to detect a magnetic field generated by the first current; and a second receiver coil arranged to detect a magnetic field generated by the second current, the magnetic field generated by the first current and the magnetic field generated by the second current providing a measure of whether a crack is present in the portion of the strip. ## Claims ### Claim 1 An arrangement for a metal making process for detecting cracks along a strip of a metallic material moving in relation to the arrangement, the arrangement comprising: a coil arrangement having: a first winding portion extending in a first direction for inducing a first current in the first direction in a portion of the strip, a second winding portion extending in a second direction for inducing a second current in the second direction in the portion of the strip, the first direction and the second direction intersecting each other, a first receiver coil arranged to detect a magnetic field generated by the first current, and a second receiver coil arranged to detect a magnetic field generated by the second current, the magnetic field generated by the first current and the magnetic field generated by the second current providing a measure of whether a crack is present in the portion of the strip and a direction of the crack, wherein the first winding portion is arranged at a first distance from the first receiver coil; and a protection member arranged to be sandwiched between the coil arrangement and a metallic material when the arrangement is in use, to maintain a second distance between the first winding portion and a surface of the metallic material, wherein the first distance and the second distance differ less than 40%. ### Claim 2 (depends on 1) The arrangement as claimed in claim 1, wherein the first direction and the second direction are essentially perpendicular. ### Claim 3 (depends on 1) The arrangement as claimed in claim 1, wherein the second winding portion is arranged downstream of the first winding portion with respect to a direction of movement of a metallic material during crack inspection thereof. ### Claim 4 (depends on 1) The arrangement as claimed in claim 1, wherein the first receiver coil is arranged at a side of the first winding portion and the second receiver coil is arranged at a side of the second winding portion, the first receiver coil and the second receiver coil both being arranged in the same plane as the first winding portion and the second winding portion. ### Claim 5 (depends on 4) The arrangement as claimed in claim 4, wherein a winding of the first receiver coil is arranged in parallel with the first winding portion and a winding of the second receiver coil is arranged in parallel with the second winding portion. ### Claim 6 (depends on 5) The arrangement as claimed in claim 5, wherein the first winding portion has an essentially constant direction of extension along a distance where the first winding portion is parallel with the winding of the first receiver coil, and the second winding portion has an essentially constant direction of extension along a distance where the second winding portion is parallel with the winding of the second receiver coil. ### Claim 7 (depends on 1) The arrangement as claimed in claim 1, comprising a signal generator arranged to feed a time-varying current to the first winding portion and the second winding portion for inducing the first current and the second current in the metallic material. ### Claim 8 (depends on 1) The arrangement as claimed in claim 1, wherein the first winding portion defines a first leg of an essentially right angled triangular transmitter coil and the second winding portion defines a second leg of the essentially triangular transmitter coil, the first leg and the second leg being essentially perpendicular legs. ### Claim 9 (depends on 1) The arrangement as claimed in claim 1, wherein the first winding portion and the second winding portion form part of electrically separated coils, each of the first winding portion and the second winding portion being arranged to be fed with an individual time-varying current. ### Claim 10 (depends on 9) The arrangement as claimed in claim 9, wherein each of the first winding portion and the second winding portion form part of a respective rectangular shaped transmitter coil. ### Claim 11 (depends on 7) The arrangement as claimed in claim 7, wherein the time-varying current is a pulse train. ### Claim 12 (depends on 7) The arrangement as claimed in claim 7, comprising a control unit for controlling the signal generator to alternatingly provide the time-varying current to each of the first winding portion and the second winding portion to thereby alternatingly induce the first current and the second current in the metallic material. ### Claim 13 (depends on 1) The arrangement as claimed in claim 1, comprising a computing unit arranged to receive signals based on the magnetic field detected by the first receiver coil and on the magnetic field detected by the second receiver coil for determining whether a crack is present in the strip. ### Claim 14 (depends on 13) The arrangement as claimed in claim 13, wherein the computing unit is arranged to determine a direction of extension of a detected crack based on the magnetic field detected by the first receiver coil and on the magnetic field detected by the second receiver coil. ### Claim 15 (depends on 9) The arrangement as claimed in claim 9, comprising: a third receiver coil having a winding arranged along the same axis as the first receiver coil, the winding of the third receiver coil being arranged to detect the magnetic field generated by the first current. ### Claim 16 (depends on 15) The arrangement claimed in claim 15, having a third winding portion parallel with the second winding portion for inducing a third current in the metallic material, and a fourth receiver coil having a winding arranged in parallel with the winding of the second receiver coil, the winding of the fourth receiver coil being arranged to detect a magnetic field generated by the third current in the metallic material. ### Claim 17 (depends on 1) The arrangement as claimed in claim 1, wherein the first winding portion forms part of a transmitter coil, which transmitter coil has a smallest dimension, in a plane parallel to a surface of a metallic material to be inspected for cracks when the surface is being inspected for cracks, which is at least twice as large as the second distance. ### Claim 18 (depends on 17) The arrangement as claimed in claim 17, wherein the smallest dimension of the transmitter coil is at least three times as large as the second distance. ### Claim 19 (depends on 1) The arrangement as claimed in claim 1, wherein the first distance and the second distance differ less than 20%. ### Claim 20 (depends on 1) The arrangement as claimed in claim 1, wherein the second winding portion arranged at a first distance from the second receiver coil, wherein the protection member maintains a second distance between the second winding portion and a surface of the metallic material, wherein the first distance and the second distance differ less than 40%. ### Claim 21 (depends on 20) The arrangement as claimed in claim 20, wherein the first distance and the second distance differ less than 20%. ### Claim 22 (depends on 20) The arrangement as claimed in claim 20, wherein the second winding portion forms part of a transmitter coil, which transmitter coil has a smallest dimension, in a plane parallel to a surface of a metallic material to be inspected for cracks when the surface is being inspected for cracks, which is at least twice as large as the second distance. ### Claim 23 (depends on 22) The arrangement as claimed in claim 22, wherein the smallest dimension of the transmitter coil is at least three times as large as the second distance.