1. Discussion on the selection of one by one tracking scheme for seamless steel pipe in hot continuous rolling process
(1) Logic “soft” tracking, that is, the steel pipe can be tracked one by one simply through all kinds of logic tracking signals, detection information, production plan information, production process information, production performance information, equipment status information, etc. on the line without adding additional marks. For hot rolling production line, whether it is feeding, conveying, normal rolling process, or temporary downline process, steel pipes (or billets) are completed by branch, interval, with the condition of logical “soft” tracking. Therefore, for the hot rolling production line, in order to avoid the above technical difficulties of “red steel” and “roll rolling” in the face of physical marking, the choice of logical “soft” tracking is a relatively compromise idea.
(2) The method of additional physical marker + machine (camera) reading and recognition is adopted. For finishing production line in advance, because there are a row material, a large number of steel pipe production process with dense transverse/dial material, steel tube bundles, such as process, will inevitably occur steel pipe order random dislocation phenomenon, rely on “soft” logical track has been unable to achieve the function of steel pipe line by the tracking, this kind of situation will need to use extra physical token + machine readable recognition way, From the concrete implementation form, there are mainly the following physical trace marking methods for choice:
①Steel pipe outer wall spray code.
As mentioned above, this method is a widely used marking method for steel pipes such as silk wire in pipe processing. There are mainly three types of jet printing codes: two-dimensional code, barcode and digital code. In order to improve the tracking accuracy, at least two marking methods are often used in practical applications. In addition, in order to improve the tracking identification, you can spray a layer of white primer on the identification part.
The main advantages of this labeling method are convenient operation, fast, less investment; The main disadvantage is that the identification station needs to set up auxiliary rotating equipment to ensure that the steel pipe can be identified while rotating, so as to avoid the interference of the disorderly “rolling” of the steel pipe during transportation to other parts. In addition, the identification code of the outer wall of the steel pipe may be worn to different degrees after roller rolling of the straightener, which may affect the subsequent identification effect.
② Label the inner wall of steel pipes.
In order to realize automatic application, this method usually requires the introduction of robots to perform marking and identification respectively: marking station by robot will be printed with QR code or barcode label to the inner wall of the steel pipe designated position, identification station by robot clamping camera to the inner wall of the specified steel pipe rotation scan 360°.The main advantages of this method are that it can avoid the identification code wear problem which may occur in the steel pipe outer wall coding, and the identification station does not need to set additional auxiliary rotating equipment. The main disadvantages are high input cost and may not be suitable for small diameter tubes due to their limited inner hole space.
③ Steel pipe end jet coding.
The steel tube end face coding method is similar to the above “steel tube outer wall coding” method, mainly spraying binary code, bar code or digital code, the only difference is that the spraying site is selected on the steel tube end face.
This method has many advantages, including convenient operation, rapid operation, less investment, can avoid the problem of identification code wear that may occur in the steel pipe outer wall code printing, identification station does not need to set additional auxiliary rotating equipment, etc. However, there are also two prominent hidden dangers. One is that the spraying surface area is too small for small diameter thin-walled pipes, which will affect the spraying quality. Second, there are different degrees of burr on the end face of the steel pipe cut by the pipe row saw, and the end face is not smooth enough, which may affect the recognition effect.
In fact, simply from the type of marking code, in addition to the above coding and labeling, there are laser coding, but some steel pipe users think that this way will damage the thin-walled steel pipe, do not approve of this way of delivery; From recognition way, in addition to common way of camera play according to the above, in theory also can be used in a radio frequency identification technology and visual identification technology, these two approaches both in technical level, can implement level, or investment price level remains to be further in-depth discussion, at least for now in the field of steel rolling plate of material tracking application have not been reported.
2. Brief analysis of the application prospect of seamless steel pipe tracking in hot continuous rolling process
As mentioned above, pipe tracking technology is only the basic premise and necessary condition to realize intelligent manufacturing. Once this technology is successfully implemented in hot continuous rolling process, how to connect it with quality control and efficient production, so as to truly achieve high-quality, efficient and intelligent production, is worth thinking about in advance.
(1) Realize the numerical payment. According to the end user’s requirements, the relevant data and information of each production process and testing process of each steel pipe can be automatically obtained by scanning the code.
(2) To achieve optimal configuration of parameters by fully combining pipe tracking technology with big data analysis technology and online automatic detection technology of steel pipe, aiming at product quality and dimensional accuracy, to achieve the optimal configuration of process and equipment performance parameters of each production process.
(3) Realize automatic quality traceability and control. By steel tube by tracking technology, will test process that is associated with rolling process, so as to realize the headwaters of each steel pipe product quality defects and perforation, rolling and tension reducing deformation process of automatic tracing, not only for the process, improve product quality stability, create conditions, but also to production line for the development of new technology, new products in the future.