المواقع الساخنة في صناعة التتبع في الوقت الفعلي ، ومشاركة المعلومات الموثوقة ، ومساعدتك على فهم الفرص التجارية
تأثير نوع الصفائح المدلفنة على البارد مع عمليات مختلفة على التخليل والاستقامة
تاريخ الإصدار:
2024-04-29
يعد تسطيح شريط الفولاذ المقاوم للصدأ المدلفن على البارد أحد المؤشرات المهمة لعكس المنتج ، حيث أصبحت عملية التسطيح والرملي والنقش والطحن 8K ومتطلبات أخرى لسطح الشريط أكثر وأكثر صرامة ، في التلدين المتداول والتخليل من الشريط ، أصبحت عملية ضرورية لمزيد من الشركات المصنعة. أثناء عملية الدرفلة على البارد لشريط الفولاذ المقاوم للصدأ ، يحتوي الفولاذ الشريطي على عيوب في الصفائح بسبب ضعف شكل لفة وشكل فجوة لفة رديئة. تحدث هذه العيوب نتيجة للتمديد الطولي غير المستوي للشريط في اتجاه العرض واضطراب الإجهاد المتداول. بعد إعادة التبلور التلدين والتخليل والتسوية ، من أجل القضاء على عيوب الصفائح في الشريط وجعل الإجهاد الداخلي يميل إلى التوحيد ، من الضروري رسم الشريط وتصويبه لزيادة تحسين تسطيح الشريط.
The flatness of cold-rolled stainless steel strip is one of the important indicators to reflect the product, with the downstream process flat, sanding, embossing, grinding 8K and other requirements for the flatness of the strip is becoming more and more stringent, in the rolling annealing and pickling of the strip straightening, has become a necessary process for more and more manufacturers.
During the cold rolling process of stainless steel strip, the strip steel has plate defects due to poor roll shape and poor roll gap shape. These defects occur as a result of the uneven longitudinal extension of the strip in the width direction and the disturbance of the rolling stress. After recrystallization annealing, pickling and leveling, in order to eliminate the plate defects of the strip and make the internal stress tend to be uniform, it is necessary to draw and straighten the strip to further improve the flatness of the strip.
The working principle of 1. straightening machine
When the strip steel is bent on the small diameter roller, tension is applied at the same time. Due to the simultaneous existence of bending and deformation, the strip steel is under the tension far below the yield limit of the material, and the strip center layer produces plastic extension, thus improving the strip steel plate shape. The strip steel has been stretched and bent many times in the straightening machine, so that the length of the internal fiber tends to be equal after plastic deformation, so that the strip steel obtains a good straightness.
Structure of 2. straightening machine (1550 type) (as shown in Fig. 1)
(1)1# and 2# bending roller groups: each includes upper and lower φ32mm bending roller groups: each φ32mm roller system includes working roller φ32mm × 1550mm (one), intermediate roller φ40mm × 1550mm (two), and support roller φ74mm × 192mm (three rows, 6 in each row, 18 in total).
(2) Anti-transverse bending straightening roller group: it includes two φ200mm × 1550mm upper straightening rollers and a set of φ50mm lower straightening roller group, of which the φ50mm lower straightening roller group consists of working roller φ50mm × 1550mm (one), intermediate roller φ40mm × 1550mm (two) and support roller φ74mm × 192mm(18). It is mainly used for finishing the transverse deformation of the outlet plate shape.
(3) Anti-longitudinal bending straightening roller group: The anti-longitudinal bending roller group consists of working roller φ70mm × 1550mm (one) and supporting roller φ74mm × 192mm (two rows, 6 in each row, 12 in total). It is mainly used for finishing the longitudinal deformation of the outlet plate shape.
3. common plate defect adjustment method
After the strip passes through the straightening machine, most of the reasons for the plate quality problems are caused by the insufficient installation accuracy of the straightening machine and the front and rear tension roller groups. When there is a quality problem with the strip steel, first check the levelness and verticality of the working rollers and straightening roller groups of the straightening machine, and check the levelness of the front and rear tension roller groups and the verticality of the tension roller groups and the strip steel production line. When the installation accuracy of the tension straightening machine and the front and rear tension roller groups meets the installation requirements, the adjustment principle of the tension straightening machine is to improve the quality of the plate by changing the cutting amount of the work roller and the elongation of the strip steel. The following are several typical plate defect adjustment methods (as shown in Figure 2):
Note: The following debugging methods are applied to ensure that the installation accuracy of the tension straightener and the front and rear tension roller sets meets the installation requirements.
Debugging method when the one-sided wave of (I) strip steel is obvious after passing through the straightening machine
After the strip passes through the straightening machine, the one-sided wave is obvious. This defect can be made up by changing the levelness of the working roll, that is, trying to raise the working roll without the side wave. By increasing the elastic-plastic deformation of the strip without the side wave, the consistency of the fiber length on the strip surface is improved, and the single-side wave of the strip is eliminated.
Debugging method of (II) strip steel after passing through the straightening machine when the side waves on both sides are obvious
After the strip steel passes through the straightening machine, the side waves on both sides are obvious. First of all, it is necessary to analyze whether the elongation is appropriate. The elongation rate is too small, and the improvement effect of strip steel plate is not obvious. If the elongation rate is too large, the extension deformation of tension straightening is too large, which will also cause side waves on both sides. Therefore, it must be analyzed according to the original plate type and actual elongation. Secondly, it is necessary to consider the influence of strip steel itself. If it is suddenly found that there are side waves on both sides of a coil of strip steel under normal conditions of other strip steel, it is likely that the thickness of the strip steel itself or the incomplete annealing in the middle of the strip steel.
Debugging method of (III) strip steel when the medium wave is obvious after passing through the tension straightener
When the medium wave of the strip after the straightening machine is obvious, it can be eliminated by increasing the elongation. When the original elongation is already large, it can be eliminated by increasing the amount of work roll insertion.
Debugging Method of (IV) Strip Steel with Obvious Warpage after Tightening Machine
When the warping of the strip steel is obvious after passing through the straightening machine, it can be eliminated by increasing or decreasing the anti-transverse bending straightening roller, and the specific adjustment range depends on the sample piece cut in the middle of the strip steel.
Debugging Method of (V) Strip Steel After Straightening Machine
When the C warping of the strip steel is obvious after passing through the straightening machine, it can be eliminated by increasing or decreasing the anti-longitudinal bending straightening roller. The specific adjustment range can be determined by visual inspection of the strip steel detection platform or partial cutting and sampling.
The incoming plate type is very good, and after the straightening machine, the quality of the plate type becomes worse. Can cause this phenomenon is the first strip in the furnace heating time is not enough, resulting in incomplete annealing caused. Another reason is that when the strip is cooled, the cooling effect of the edge and the center is inconsistent, resulting in high strength and poor toughness in the middle part, low strength and good plasticity in the side part, which is caused by the same force when pulling and straightening, resulting in different deformation. This phenomenon can also be caused when the thickness of the strip is uneven. To solve this problem, only by improving the strip annealing process, improve the quality of incoming materials can be solved.
Effect of 4. different rolling processes on plate shape
With the emergence of cold rolling mills, some cold rolling mills have both continuous rolling mills and single rolling mills, so annealing and pickling need to deal with two different processes of incoming plate type. In this case, how to adjust the tension parameters to ensure that the customer is satisfied with the plate is very important. The following is a description of the plate type of strip steel produced by the continuous mill and the single mill, and the possible effects of pickling and drawing:
The difference between the ability of (I) continuous rolling mill and single rolling mill to correct the raw material plate shape.
For the plate type problems left over from raw materials (generally referring to white leather rolls), the single rolling mill passes through multi-pass reciprocating rolling, and plate type rollers are provided at the entrance and exit to feed back the plate type situation in time. The operator can adjust the plate type in each pass. If one pass is not adjusted well, it can also be adjusted in the next pass, which can effectively improve the plate type defects of raw materials. However, the continuous rolling mill is also equipped with plate type rollers at the entrance and exit, but due to continuous rolling, the timeliness of correcting the plate type is not high once. When rolling thick materials, the strip steel has been rolled before the plate type is usually adjusted. Therefore, the continuous rolling mill's ability to correct the plate problem of raw materials is relatively poor.
Differences in plate control between (II) continuous rolling and single rolling processes
Due to the limitation of the number of cold rolling mill brackets (generally five brackets and six brackets), the number of rolling passes is generally less than that of single rolling mill. If a bracket failure is encountered, the production of throwing brackets will also occur, thus the number of rolling passes will be less. Therefore, in order to obtain a higher rolling rate, the rolling rate of the first bracket is very important, generally between 25% and 30%. When the strip passes through the first bracket, in the case of such a large rolling rate rolling, there will be medium waves, and the degree of medium waves will increase with the increase of the thickness of the strip. After the first bracket large rolling rate of work hardening, in the case of high-speed operation, the subsequent bracket on the plate correction capacity is very limited. The single mill does not have this problem, it can be adjusted by the operator in each pass, so that the final plate tends to be reasonable.
Influence of (III) Different Mill Plate Type on Adjustment of Tightening Machine
Because there are some differences in the strip type produced by different rolling processes, there are some differences in the adjustment of the plate type of the same straightening machine. The defects of strip steel produced by different rolling processes, such as side wave, medium wave, 1/4 wave, warping, etc., are basically the same through the adjustment method of the straightening machine, but the continuous rolling mill will form C warping to the non-reference plane after the back bracket is rolled because the first bracket is the medium wave of strip steel. Therefore, when adjusting the anti-longitudinal bending straightening roller, the straightening machine should give the strip steel a reverse bending as compensation, and the plate shape adjusted by the straightening machine should be tilted to the reference plane C (as shown in Figure 3) as a reference, so that the strip steel can obtain the required straightness. However, the strip steel produced by the single rolling mill does not have the problem of C- warping. The plate type adjusted by the pull-straightening machine is linear (as shown in Figure 3) as a reference, and the strip steel can be obtained to obtain the required straightness.
Since the C- warping produced by continuous rolling has an increasing relationship with the increasing thickness of the strip, when adjusting the warping H of the straightener, it should also increase with the increasing thickness of the finished product. At present, the thickness of the regular finished product of the general wide plate cold rolling plant is between 0.3 and 3.0mm, and the adjusted warpage h is also between 10 and 40mm. the specific thickness range depends on the actual debugging.
5. Conclusion
Stainless steel strip is left over from different cold rolling processes or its own plate problems, which will bring some influence on the adjustment of the drawing and straightening process. The defects such as side waves, medium waves, 1/4 waves, warping and the like are basically the same through the adjustment method of the straightening machine, while the c-warping caused by the continuous rolling process needs to be adjusted differently, and the adjusted warping degree h increases with the thickness of the finished strip to ensure the flatness of the final strip.
الكلمات الرئيسية:
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Shanxi Xinruida Metallurgical Machinery Manufacturing Co., Ltd.
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العنوان: حديقة قرية شيفنيانغ الصناعية ، مقاطعة جياوتشنغ ، مقاطعة شانكسي