Typical application cases II: Bars vortex testing

1. Overview of bars vortex testing        
Bars vortex detection is usually offline automatic detection (as shown in figure 13), generally uses two ways such as traverse type detection and rotation detection: traverse type testing is mainly for mutation or lateral wounds; rotating test is mainly aimed at the longitudinal crack or graded wound.
Traverse type detection is used for detecting surface and near surface defects, rotating detection normally only surface defects.
For ferromagnetic bars, when using traverse type test, a magnetizing device should be configured; for rotating detection, or testing of non-ferromagnetic material, do not need magnetization.
2. Bars vortex testing process      
Fig 13 is an integration equipment for steel bar traverse type detecting and rotate detecting , traverse type detection is marked on left side of red circle as shown in figure 13. Tested steel bars pass through roller transmission system and traverse from the middle of traverse type probe, complete testing.
And whether using the magnetizing device, depend on whether the materials is ferromagnetic material. The ferromagnetic material needs to increase the magnetizing device, but non-ferromagnetic material does not require.
Magnetizing device actual diagram as shown in figure 14, traverse type probe actual diagram as shown in figure 15.
When using magnetic device, probe is installed in magnetization device, steel pipe is in and out from the inner hole in magnetizing device left and right sides, as shown in figure 14.
Rotating vortex detection is shown in marked red circle on the right side of figure 13, the device uses the method that bars go forward straightly and levelly, the probe spins in place, and is mainly used for detecting surface longitudinal defects. Steel bar traverses from the rotation mechanism of probe uniformly and stably by driving clamp roller. Steel bar level movement speed depends on probe rotating velocity and probe diameter, you must ensure that the probe’s progress step distance is not greater than pitch, otherwise there will be a leak detection.
The point probe used for rotating detection is commonly the combination of multiple probes, coil diameter of each probe is not too big. The outline of ordinary single point probe is shown in figure 16.
Fig 16. point probe
3. Bars vortex testing technology characteristics  
·   High detection efficiency: vortex testing with top speed of near km/min, ensure product to be completely nondestructively tested.
·   Long service life: using non-contact detection, the probe do not contact directly with parts and not easy to wear.
·   High degree of automation, can communicate with PLC programmable control, realize automation works such as feeding, alarming, marking, picking up the waste, unloading, etc.
·   High temperature resistant, with specially designing and processing of sensor, can test under harsh environment of high temperature of near kilo-degrees.
·   With powerful detection functions: in addition to defect detection, also can measure wall thickness, coating and clad layer thickness, prevent different type steel from mixing, etc.
·   With good economy and relatively low costs.
·   Security: the detection technology will not produce any radiation to human body.
4. Recommend detection instrument for bars vortex test  
Eddysun company’s instruments are designed with the most advanced digital electronic technology and microcomputer technology, and suitable for online or offline detection. The instruments can output different real-time signal and delayed signal according to the types and features of detected parts, the instruments can form a complete set flexibly with mechanical and electrical automation equipments to achieve all automatic detections such as: automatic feeding, detecting, unloading and sorting (separate qualified products and wastes). The instruments can also be installed directly on production line for real-time on-line detection, and separate qualified products and wastes by connecting with PLC programmable controller.
The instruments can connect externally with code disc, realize high precision marking and automatic sorting function nothing to do with the unit speed. At the same time, the instruments can also be connected to A – scan switch to realize A - scan mode detecting, and automatically cut head and tail vortex signal of each steel pipe, conveniently and intuitively show the number of each tube defects, location, and cumulatively detect the quantity of tested products and wastes
Commonly used models:  EEC-22+ 、EEC-22SEEC-30SEEC-35+ 、EEC-35++EEC-39EEC-24EEC-24KEEC-33EEC-51EEC-58 
Commonly used options: traverse type magnetic saturatordemagnetization devicemarking machineacousto-optic alarmpoint probe out traverse type probeguide bushcabinet
5. Bars vortex testing application cases    
Jiangsu ShenYuan special steel co., LTD
Guizhou aerospace precision work manufacturing co., LTD.
Changzhou NKT cables Group GmbH
ShengDa Copper co., LTD. TaiXing
Yantai Jinhui Copper Industry co., LTD.