Yantai Mannur Superalloy Co., Ltd. is a company mainly producing petrochemical pipelines. Its main equipment is boring machine and lathe. Boring machine is mainly used to bore the inner hole of pipe, and lathe is mainly used to turn groove, bend pipe and excircle. This is the first set of production equipment I learned in the company. As for my work, it is arranged by the leader, and his post is piping. The so-called piping is simply the production process of selecting n pipe sections from the processed petrochemical pipeline and welding them into a straight long pipe according to the size requirements and technical requirements of the drawings (n is according to the technical requirements of the drawings, but the total length of these pipe sections should meet the requirements of the drawings).
After a week's study, in addition to learning piping, I also have some comprehensive understanding of the general production process of the company, which I think is very important for my better work. After this week's understanding, I learned. The petrochemical pipes produced by the company are mainly used in the chemical industry, such as processing benzene, styrene and other chemical products, oil pipelines and so on. Moreover, these products have quite high requirements for pipes. It requires that these pipes must be resistant to high temperature and corrosion, and also ensure certain mechanical properties and test pressure (hydrostatic test).
This kind of pipe is produced by casting, and the production method is centrifugal casting. In order to meet the technical requirements of high temperature resistance and corrosion resistance, this special stainless steel is needed. This special stainless steel mainly contains nickel and cadmium. Therefore, generally produced pipes are made of 25-35, 35-45, 25-20 and 28-48 materials (25-35 refers to materials containing 25% cadmium and 45% nickel).
The material is very important. Only by choosing this one correctly can we proceed to the next step. Next is the stove. Pay attention to the temperature. Because of this special steel, its temperature is higher than the general one, about 1643℃. The third is centrifugal casting. In this respect, the concentration of paint, the heating temperature, the rotating speed of mold cylinder and the pouring speed of molten steel should be controlled. Any problem will lead to the quality of production. If the rotating speed is not enough, looseness may occur, and if the time sequence of molten steel is intermittent, interlayer may occur.
After cleaning, blank inspection, shot peening, straightening, sample cutting and fluorescent air tightness, the produced pipes are drilled.
Drilling holes shall be processed according to the requirements of drawings. Generally, the tolerance is between 0.5mm- 1mm, and the surface roughness is between 1.6-6.3, depending on the technical requirements. The main problems in drilling are tool withdrawal marks and vibrating tools. In fact, most of the reasons for this situation are that the bed has entered the end of its service life.
The blank after boring is the workpiece. After inspection by the internal inspector of machining, it will be sent to the quality inspection department for inspection. After passing the size inspection and eddy current inspection, it can be sent to the distribution area.
The first thing to do when entering the distribution area is to color the inner hole. Its purpose is to check whether these pipes are qualified, whether there is looseness or slag inclusion, and to prepare for piping. If there are some unqualified products, such as slag inclusion, looseness, interlayer, etc. The only solution is to cut off the problematic part. Then re-color the remaining pipes, and they can be used after passing the test.
After the pipes are assembled, the groove should be turned over. The so-called chamfering is to turn both ends of each pipe section into V-shaped or U-shaped chamfers according to the requirements of drawings. Its purpose is to make a base (the so-called base is to connect the pipe sections by argon arc welding). After the prepared pipe section is turned over, it is necessary to color the groove and measure the size by the quality inspection department. Size measurement should not only check whether the pipe length is correct, but also check whether the groove size is appropriate. Only after passing the inspection by the quality inspection department can it be transferred to the welding workshop. The main working procedures to be completed in the welding workshop are priming, filling, welding seam coloring, root grinding and welding inspection. After these are completed, the processes to be carried out are hydrostatic test and X-ray shooting. If not all processes are qualified. Then this process is basically over, and finally it is sandblasting packaging.
To sum up, it can be summarized as follows: according to customer requirements-material selection-casting-blank cleaning-shot blasting-straightening-fluorescent air tightness-drilling-dimensional inspection-cavity coloring-piping-groove-backing weld-filling welding-weld coloring-welding inspection.
After a period of study and thinking, the understanding of these makes me understand the importance of the production process. The production process is interlocking, and every link has errors, which directly leads to the normal operation of the next process. Knowing this, I know the importance of my work. Only by knowing ourselves and ourselves can we do a good job.
It can be said that I only heard about the term pipeline when I entered the company. I have never been exposed to this term before. When I first started my on-the-job study, what my master told me was not so profound. This paper briefly introduces the matters needing attention in the work. He said: "The technical content required for this position is not high. There is no need for technology such as machining parts. The key to this position is carefulness, patience and good organization and distribution skills. For example, with so many pipe sections, you should reasonably arrange where to put them, where to put those and where to put the project. Of course, you can put it anywhere, but once it is messed up, it will directly affect the production and affect the whole production process. If you can't match the pipe, then the beveling machine is dead. Do you want to stop? If the beveling machine dies, the whole welding workshop will be shut down soon. In this place, you must be clear-headed and never make mistakes. " In addition to telling me this, the master also told me some knowledge about how to blow the pipe. After the teacher's explanation, I learned what kind of piping. For example, the straight pipe size required in the drawing is 12906+6, and it is required to be welded by four pipe sections at most, and the shortest pipe section is not less than1.2m. Actually, according to the general situation, I only need to find four pipe sections from all the pipe sections, so that the sum of these four pipe sections is equal to 12906 and/kloc-0. However, there are two problems. First, it needs to be considered that the beveling machine must close the knife when machining, and the burr needs to be polished after machining the beveling, so that each pipe section may be about 0.5mm short, even in millimeters, which requires me to measure only the length of the pipe section (for example, the length of the pipe section is a little more than 2 103mm, so it will be recorded as 2660. Secondly, there is the problem of weld shrinkage in backing weld. According to experience, the weld shrinkage of each material is different, some weld shrinkage is 2mm, some weld shrinkage is 1.6mm, and some weld shrinkage is basically not. If the size mentioned above is that, it is impossible to manage it according to the range of12906-12912. Considering the shrinkage of weld, it can be piping according to 129 16. In this way, four sections of pipe and three welds are assembled and welded within the range of 12906+6. Meet the requirements of the drawings.