The design application in Ray detecting

The design application in ray detecting

The digitized ray detecting technique based on CS detector as recording medium ,detecting precision is high、temperature adaptability is good、structure adaptability is strong 。CMOS ray scanning detector detect line array ,it need to  conduct relevant scanning activities when detecting,gradually collect and spell into a whole projective images。 Introducing detecting equipment design ，complete detector fix、position adjustment and realize relevant movement with detecting workpiece，introducing detector configuration and calibration 、penetrative ways selection 、moving speed control、detecting parameter optimization、flaw quantitative analysis and picture archive management and so on in detecting application. Application results show that being technology optimization ，CMOS detector can realize ray detection of most products accessories 。And finally analyze questions that exists in the application and its next research direction 。

1. CMOS detector profile

Ray detecting technique takes advantage of X ray to detect discontinuity inside of material ,and display image on the recording medium,along with the development of technique,ray detecting has been extended constantly from traditional photography method that use film as recording medium .forming multiple digitized ray detecting method,such as digitized dealing technique on film/ray real time imaging technique/computer ray imaging system and ray digital direct imaging detecting technique,in actual application,it needs to choose a suitable method according to resolution and relevant sensitivity.relative to other ray recording medium,CMOS (complimentary mental oxide silicium )technique has more advantages.At present ,the smallest dimension of CMOS detector can up to 30μm ，detecting precision is higher，temperature adaptability is good ,structure adaptability is powerful。

Comparing with enormous intensifier imaging system，CMOS ray scanning detector is small size，internal chips have high integration level。Compared with CCD imaging ways,every probe point of CMOS has its own amplifier to do individual configuration 。CMOS transform received ray into light by transform screen in its own interior, and straightly transform light into electron by probe point。Every probe point unit has its own amplifier to make signal amplification。And finally do A/D transformation on signal in detector and forming binary system that transmit to computer。CMOS mainly suitable for 20～320 kV ray energy，80/μm space resolution ，the detecting resolution is 6 lp/mm when there is no geometric amplification 。Detecting image is up to 40% grayscale。

Detecting application of CMOS detector .

2.1 detecting process

Due to CMOS ray detecting units arranged in line array ，under stationary state can only get a line in the projected image formed by ray penetrates detected object 。For achieving the image of detected object , requiring to do relative scanning movement，gradually collect and spell into a whole projected image。When Obtain detecting image,it requires ray energy fluctuation as small as possible and can work for long time。Therefore ,the writer adopts constant pressure type Ray source(YX-LON MG325) the maximum voltage is 320kv, big focus is 3.0mm,small focus is 2.0mm，adopting CMOS linear X ray scanning detector to do ray detection procedure is :detector configuration and calibration ---make sure transillumination mode ，adjust position parameter ---relative movement ，obtain scanning image---image dealing ,flaw analysis。

2.2  detecting equipment with probe design

Imaging unit of Detector (line array ) needs match with center line of ray bundle very well ,the relative position inclined or out of line is prohibited 。Therefore ,it needs to design suitable imaging equipment ,so as to complete detector fixposition adjustment and realize relative movement with detecting workpiece。The equipment need to be convenient to get in and get out (cylindric equipment)，it should equipped with sensitivity and more suitability (detecting different kinds of workpiece。)

Based on convenient and practical principle，do equipment with detecting design on basis of existing ray real time imaging system。Namely put workpiece on working stage when detecting ,realizing left and right translation、rotate around the vertical axis；the detector is fixed on ray real time imaging system intensifier axis of movement，realizing veetol and front and back movement。In addition，detector can realize a certain angle rotation adjustment 。By combining with real time imaging detecting system ， it can realize raydetection of multiple types of workpiece。Moreover，when applying ,this still needs to design fixed positioning equipment with probe for workpiece。

2.3  detector configuration and calibration

It needs to appoint the kind parameter of imaging when it is first time to use detector (length and withstand voltage ) ，so as to make sure practicable minimum integration time,before the detector is working normally ，it must be configured and calibrated ,so as to under certain conditions make all bias on output and gain output of detecting units are the same。

For new detecting target ，firstly deploy relevant parameter of collecting image (integration time、scanning precision、and whether using average value ) ,then begin to calibrate detector。It needs to consider effects of focal length and object distance 。Normal calibration needs three steps:1. Switch off ray source，The detector is being offset calibration 。2. switch on ray source，adjust to current and voltage value that detection needs，make line array output signal of detector reach to maximum but not saturation，3.adjust ray energy,make line array output signal reduce to the half of maximum signal，calibration result is saved in the form of file，and be used for detecting in the future，but if its calibration parameter needs to be altered after using，then it needs to recalibrate can be detected。

For most detecting objects ，the applied current 、voltage is higher during practical detection，the output signal has been saturated when doing detector calibration 。To solve this problem，it is according to inspection situation of  different thickness ,designing relative inspecting board for calibration。Inspecting board thickness is even ，after finishing the first step of calibration put inspecting board on the ray source window，then switch on ray and continue next step of calibration operation。

2.4  comply with ways selection

(1)moving ways is suitable for ray detection of slap weld types workpiece ,when inspecting ,keeping the position of detector and ray source is relative fixed，put workpiece on the objective table and along with X axis moving at suitable speed，for circumferential weld on the pipe 、cylinder,if adopts  translational motion way imaging ，the image that collected is oval perspective images,only central area images can be used as detecting result assessment，and needs to rotate multiple angles to complete whole detection，decrease detecting sensitivity，some situations that can be realized transillumination detection due to thickness is too thick。

(2)Rotating ways requires to adjust relative position make workpiece in the center of gyration of objective stage ,and in the same line with ray bundle center、detector center,for cylinder workpiece，make detector put inside the workpiece by the equipment with probe，as much as possible to touch detecting part，adopting the way of single wall single-image to do transillumination;for pipe type and cylinder workpiece with small inner diameter,adopt double walls transillumination ways; rotating certain angle can make transillumination area being image,it can improve detecting efficiency effectively。For rotary workpiece ,adopting rotatory ways imaging has prominent advantages ,improving picture quality ,reduce detecting time。

2.5 moving speed control

Due to detector must has relative movement to imaging ,therefore it needs to control moving speed under a reasonable range。If the speed is not suitable ,then the image that got will exist stretched and compressed phenomenon。In addition ,the resolution is more ，the image noise is less, moving speed is low。

2.7  flaw quantitative detection 

Need to make calculated or known precise dimension specimen closely touch one side of detected weld and imaging with weld simultaneously when doing image dimension measuring。Before each assessment,a calibration should be done，comparing or transform image dimension into practical dimension by equation when flaw detecting，for this ,designing specified measuring evaluation for specimen,the specimen can also applied to detect that whether relative movement speed is matched。

After dimension calibration，by image dealing methods to realize flaw quantitative analysis,select Cany edge detecting algorithm to do flaw edge positioning 。And the next to do refinement treatment on detected edge,then find other endpoint to fill by searching 5*5 or bigger neighbourhood that in the center of every edge line endpoint。Completing edge point connection，eliminate clearance that in the edge detection image。Then apply pixel notation to check connectivity of every target pixel consecutive points,And do Target labelling in Closed curve ,mark different flaw for use of measuring by above operation,and finally complete flaw parameter calculation。 

2.8 image archive management 

Detecting result is saved in computer in form of digital picture，to be convenient to have unified management on detecting image，the writer designs image file management library by self, recording detecting information (workpiece name、detecting data and so on)、imaging parameter and detecting assessment result。

3.  Applied conclusion and problem analysis

CMos ray detector equipped with higher space resolution (61p/mm , inherent unintelligibility) ,detecting sensitivity is high (4096 grayscale level )。Imaging quality is superior to real time imaging system that adopts intensifier，closer or reach film photographic level,it is superior to film photographic methods and real time imaging system when it comes to image contrast。

By experiment optimization ,the detector is successfully applied to plane weld、circumferential weld and longitudinal weld and most of products accessories ray detection,improving detecting efficiency ,decreasing detecting cost.to be better promote digitized ray detecting technique ,it is necessary to do some research work in the following aspects :(1)the optimization detection and simulation of complicated workpiece ,providing theoretical support for detecting result。

(2)fast read 、dealing and analysis of big capacity image file , automation、semi automatization methods research of flaw quantitative analysis 。

(3) image file management 、transmission  (bring in PACS mode)

(4) build new digitized ray detecting standard。

 Application of ray detecting technique in steel industry

Recently,apart from smelting reduction and thin-stripe casting and so on  fundamental whole new technology revolution in steel production,improvement of controlling ability during production played an important role in generating steel  manufacturing technique progress 。Detecting technique and equipment is one of the keys of production，fierce competition factors in steel industry,detecting technique and equipment are also important constituent parts,Most of equipping automatic control system in the steel production in our country reflect recent new technique，including online detecting technique and device--online instrument device。

 1.   Steel smelting process control and detecting technique 

Modern blast-furnace smelting beneficiated burden material and high-emitting coal technologies, Raises about raw material analysis、sintering and coking process temperature and its distribution test、injected coal rate continuous detecting requirements in process control ，generating and realizing online moisture、 infrared temperature-measuring and imaging technique and development and application of gas-solid two-phase flow detection technology。Blast-furnace control is the key technique of blast-furnace ironmaking ， Under high blast temperature 、high top pressure , effective application of professional system blast furnace control mode,must with help of detecting technique 。 Furnace top and furnace stack gas analysis and internal furnace infrared thermal imaging technique has control on furnace situation。 Furnace stack temperature detecting has directive function on judging furnace situation and life of blast furnace，high speed hot metal on silicon、determining sulfur、and so on detecting technique get development and application，is reliable assurance of low-silicon smelting，accuracy of hot metal large-tonnage online weighing makes Steel logistics balance control level gets improvement。

In the steelmaking that based on converter technology,from feeding control converting to the end ,the whole process is automatic control system，so as to forecast steelmaking process control of mode control methods。Under the support of blowing oxygen、argon and furnace atmosphere analysis real time detecting and molten steel temperature、carbon content and so on high speed sampling detecting ,greatly improve controlling precision 。Online furnace gas analysis meter from infrared analyzer to mass analyzer,no matter detect accuracy or response speed，,all effectively improve predictability in the process，especially refining process control，In the steelmaking real time control abroad has received apparent effect，the mass spectrometer can analyze CO、co2、N2、H2、O2、Ar、CH4、He and so on eight kinds of gas ingredient，response time can greatly improve steelmaking process especially quality control in one second 。

2.  Continuous casting and steel rolling process control and detecting technique

 Smelting process is make fixed row material smelt into high temperature iron liquid，and by reflection control to get relative ingredient content，amount of material、temperature、ingredient are important detecting parameter in process of smelting 。The process is apart from accurate control temperature to achieve strength characteristics of material，accurate dimension and steel shape control is also one feature of rolling steel process detecting 。Product and process control are detecting technique features for detecting speed and accuracy requirement and parameter diversification。Liquid steel slag layer detection is also has high requirements on converter smelting 、 refining。Electromagnetic induction 、infrared imaging 、ray have been applied to liquid steel or slag detection so as to achieve effect of control cast steel process slag quantity.

Before development of online non-contact size detecting technique and device，high speed automation of steel rolling process is just extravagant wish 。But electromagnetism 、ray and laser one after the other applied to steel rolling process inspection，solving every kinds of detecting control requirements of steel material rolling technology ,and making production process faster、more accurate come true.The thickness accuracy of Present cold plate rolling can reach thousandth accuracy grade,the thickness of thin board is controlled within 10μm。 

The plank steel plate and plate shape control is one of the most important factors to decide steel plate quality is good or not。Cold rolled plate is always show invisible plate shape flaw when under bigger tension，because of cold rolled steel is thin ，under rolled with tension ,the straightness defect of cold rolled sheet can show uneven distribution of tension due to plank elastic,adopting method of detecting tension to detect plank shape is a more mature technique at present。But under micro tension ,hot-rolling process can adopt non-contact method to detect plank shape,hot-rolling process detection is realized under relative high vibration and high temperature、moisture and oxide layer、dust and other interference factor。  

Simultaneously in the steel rolling process ,X ray thickness and its distribution measurement 、laser measurement 、and length measurement 、infrared temperature scanning and imaging 、CCD steel plate width measurement and development of technique and equipment of shape measurement of plank ,greatly improve rolled steel automatic level and quality level。

Structure steel and tube 、wire rod are also exist such as thickness 、width、 diameter、wall thickness and so on geometric dimensioning  online real time detection control requirement，one after the other produce visible light、infrared 、laser、ray and so on measuring equipment，wire rods detecting diameter and oval gauge。Laser detecting thickness and ovality gauge、laser detecting thickness and silhouette，laser ultrasonic tube wall thickness detector make technology control get satisfied。

Steel plate coating and cladding coating on the detecting technique produce and develop detecting techniques of steel plating thickness detection、hot coating thickness measurement and organic coating thickness steel plate ， in addition ,steel plate surface flaw detector 、tube ultrasonic flaw detector and so on specified instrument are also widely used for detection control of process control and product quality of production 。