Makasa304 stainless steel plateUse and maintenance

The process flow of plastic coated copper pipe: the settlement price of 904l stainless steel plate is on the high side, and the price is stable. 904l stainless steel plate: last Friday, the steel plant made all the orders. As for the guide price, the market price rose slightly on Monday due to the positive sentiment after the festival. The working efficiency of t2 copper pipe after the expansion from Tuesday to Friday should be the same. Between the upper and lower clamping groove bodies of the alloy pipe to be flared, the end of the alloy pipe to be flared faces the flaring die, and then drives the upper clamping groove body to move down through the oil cylinder. Then, the flaring hydraulic cylinder drives the flaring die to the alloy pipe, so that the t2 copper pipe flaring die will stretch the alloy pipe port to expand its inner diameter in the alloy pipe port at the front end. The length of flared section can be 20200 mm. How to solve the crack of plastic coated copper pipe? How to solve the common fault of crack in case of improper operation during the construction of plastic coated copper pipe project? If it is not handled in time, there is a serious risk. Therefore, find more practical welding processes and then ensure the welding quality of electric welding. If we continue to develop plastic coated copper pipe materials under such circumstances, we will find that the price difference of plastic coated copper pipe with low-grade anti rust materials is different, and there are many reasons for the price difference. First, there are significant differences in production. Although it is made of stainless steel, the plastic coated copper pipe can be compared with the plastic coated copper pipe on the market.

I believe that after reading the above contents, all readers here have a clearer understanding of the automotive air conditioner copper tube. If you are interested in this product, please refer to more relevant contents. Suitable site and warehouse shall be selected for the storage of seamless air conditioning copper pipes: The site or warehouse for steel storage shall be located in a clean and well drained place away from factories and mines that produce harmful gas or dust. With the rapid development of economy, the number of cars is also fast. Nowadays, people can't live without cars. So we know what role the copper tube of automobile air conditioner plays in cars.

Makasa.Red copper inventory may end the trend of continuous decline. With the increase of production restriction of steel enterprises and the pressure of demand, the continuous decline of iron ore port inventory may end. In addition, according to the new statistics of * *, the available days of imported iron ore of steel mills are 25 days, which is one day lower than that before the National Day, and is on the high side of history. The steel mill said that at present, the iron ore inventory basically meets the production requirements. Considering the future production reduction and restriction, professional t2 copper tube manufacturers will adopt an integrated molding process to improve the yield and reduce production costs while packaging products with superior performance. As long as the above t2 copper tube quality identification method is used, it is recommended to go to the manufacturer for field inspection to determine the basic performance and quality of t2 copper tubes before large-scale mold procurement. The position of grid accessories plays a very important role in the whole construction process. The products with high cost performance and good performance certainly have a great assistance effect for the implementation of the project. In addition, it is also beneficial to the application of the middle and later stage of the forming project. There are high regulations for the performance of the grid. How about the corrosion resistance of the grid accessories? The performance of durable products such as grid and grid accessories needs to meet certain technical standards. The anti-corrosion performance of grid production and processing must be good. For manufacturers, it is necessary to improve technology and consider the performance requirements of today's construction projects. In fact, the anti-corrosion performance of accessories is not very good. It is necessary to take protective measures in the production and application process to reduce product erosion, Only by maintaining the overall reasonable layout of the grid products can we ensure the long-term performance advantages. Many technologies are required in the whole process of production and manufacturing of space truss accessories. The production and manufacturing staff should ensure the performance advantages when carrying out production and manufacturing of products. The production and processing of space truss should improve its corrosion resistance, compression resistance and strength to ensure that qualified products are produced by the original factory.

.The material cost of medical copper tube will not be less than 40 yuan. The better the material is, the higher the price will be. It is called &one cent, one cent&. Moreover in addition to the production and operation costs, labor costs, factory rent, etc., you must pay attention to the quotation below 45 yuan/square. Medical copper tubes are more and more widely used in the decoration of building exterior walls. In cold cities in the north, medical copper tubes can play a very good role in decoration and insulation. With the continuous progress of science and technology, the quality and firmness of medical copper tubes have been improved. However, as long as the decoration materials are used they will inevitably crack during installation and construction. As time goes by, there will be aging to varying degrees in daily life. Next, Zhongsheng Thermal Insulation Technology will introduce how to prevent the cracking of medical copper tubes and how to prevent the aging of medical t2 copper tubes? Let's talk about these two issues. How to prevent cracking of medical copper pipes To avoid cracks, buildings should be fully insulated, including awnings and other components. Through the quality and construction methods of external medical copper pipes, the construction quality can reach By reducing the ratio of the linear expansion coefficient of external thermal insulation materials of the building structure to the linear expansion coefficient of materials such as external decoration leveling mortar and external decoration surface, gradual changes will occur between medical copper pipes layer by layer, and the stress can be flexibly released, To prevent cracking. How to prevent medical copper tube from aging? The insulation layer of high-rise buildings shall have fire resistance , and shall have the characteristics of preventing fire spread and releasing smoke or toxic gas in case of fire. The strength and volume of materials shall not be reduced too much, and the surface shall not burst or collapse. Medical copper tube Medical copper tube is a new type of plate which is popular in China in recent years. It has many advantages, such as good heat preservation, fire insulation, sound insulation, convenient construction, beautiful appearance, etc., and is deeply welcomed by the industry. The medical copper pipe may fall during use. In order to reduce the occurrence of this kind of phenomenon, Jinan Zhongsheng Thermal Insulation Technology made a detailed ysis. Next, we will introduce the reasons for the fall of the external wall of the medical copper pipe and how to protect the medical copper pipe during installation. Reasons for the fall of the external wall of the medical copper pipe The medical copper pipe was not firmly fixed and moved, forming a push-pull effect causing local hollowing of the insulation layer, and long-term water seepage after cracks, leading to the fall of the insulation layer. 3 At the connection between the concrete beam column and the masonry, the medical copper pipe is easy to fall off due to the deformation of the masonry. 4 Scaffold holes are not solid, forming insulation layer, and local base course is not firm and damaged. 5 The surface load of the medical copper tube is too large,MakasaT2 copper bar, or the anti negative wind pressure measures are unreasonable.

What problems should we pay attention to in each production. It is a key process to weld copper pipe with correct process. Welding materials, welding speed of t2 copper pipe, welding current, welding voltage, wire arrangement, spacing, inclination and other process parameters will affect the performance of the weld. The residual stress of final welded pipe affected by forming is divided into anti-corrosion performance of copper pipe. Copper pipe is a kind of production of pipe material, which is processed into seamless square pipe. The physical properties of copper tubes are slightly weaker than those of hot-rolled steel tubes. The copper tube adopts a two-step push tube expanding machine, which integrates cone die tube expansion, data medium frequency induction heating and hydraulic press. With effective processing technology, low energy consumption, less infrastructure construction, good products, wide application fields of raw materials and products, and what are the production batches suitable for copper tube testing. When purchasing copper tubes, we pay more attention to their general possibilities and observations, but this is effective for a few customers, but it is time-consuming and labor-intensive for many customers, and may not be able to accurately distinguish between them. For such problems, it is recommended to conduct a large number of inspections within a small scope of procurement, and then the following is how to conduct inspections. The dimension tolerance of the cleanliness and wall thickness of the inner cavity of the copper tube is strict. However, in the whole process of electric welding, due to the role of the molten metal material of the air conditioning copper pipe, the thickness of the pipe at the welding point will be uneven, and the inside and outside of the welding will be uneven. This will cause energy consumption of the conveyor. At this time, the internal welding ground must be used for leveling. Next, we will take you to the production process of copper pipe - internal welding and calibration. At present, so you should decide how much to use before buying.

Four in one formula and process conditions Preparation of solution Take formula 1 as an example: mix the calculated amount of water for zinc oxide into a paste there are many things to pay attention to when purchasing copper tubes. Want to keep high when buying. What should we pay attention to when buying copper tubes next. The daily use and market are calculated according to the weight, slowly add it into the calculated amount of phosphoric acid under stirring until it is completely dissolved, then add zinc nitrate and tartaric acid, dilute it with water to 2/3 of the total volume, add sodium alkosulfonate and OP emulsion,MakasaLow alloy plate, and stir to make it completely dissolved. Then add chromium dihydrogen phosphate dissolved in dilute phosphoric acid, and add titanium sulfate. After all materials are added, dilute them to the total volume, cool them to room temperature, put a large amount of iron filings in the solution, and soak them for 2-3 days to make them contain enough ferrous ions. When the content of ferrous ion reaches above 7g/L, adjust the free acidity and total acidity of the solution to the specified value, and then the solution can be used at elevated temperature. When the ferrous ion reaches the above value, the solution is stable and the phosphating film is fine and dense. During operation, the degreasing technology of degreased copper pipe. How to make degreased copper pipe? The process flow of degreased copper tube? What are the characteristics of degreased copper tubes? Use of degreased copper tube? There are too many questions. Let's solve them at once. Everyone knows the copper tube. Nitrate reacts easily. The heater should be installed on the two walls of the tank, not on the bottom of the tank, to prevent local overheating. Stainless steel pipe or iron pipe should be used for heater, and lead pipe or copper pipe should not be used to avoid contamination of solution by impurities. What is degreased copper pipe? &The advantages of degreased copper pipe's comprehensive treatment of grease, rust removal, phosphating and passivation are described. This comprehensive treatment process can simplify the process, reduce the work area, save equipment costs, shorten working hours, improve labor productivity and reduce costs. This method can only be used in the occasions where the requirements for coating quality are not high.However, in actual production, due to the amount of oil contamination light and heavy rust, the consumption rate of each component in the solution is different, so attention should be paid to adjustment and control to maintain its due role. What is the degreasing copper tube? &I have roughly known the degreasing methods of degreasing copper tubes: solvent degreasing, alkali degreasing, ultrasonic degreasing, high pressure hot water degreasing, electrolytic degreasing, collect it together into a container, volatilize, collect and reuse the volatile solvent, and separate the pollutants from the circulation system. This method was used in the early stage, which has problems such as low cleaning efficiency, difficult maintenance, and environmental pollution. In recent years, many kinds of surfactants have been developed.

The degreased copper tube is made of oxygen free copper rod, which has good processing characteristics and can be punched, bent and other process design requirements. The surface can be subject to anti-corrosion treatment, such as nickel plating, tin plating, zinc plating, etc. The surface anti-corrosion can reach 72 hours of fog test. The surface tin plating is environment-friendly lead-free tin and the surface tin layer supports soldering. T2 degreased copper tube is mainly used for communication cabinet, transformer, charging pile, box type substation and other electrical facilities. The copper bar is harder than the plastic pipe and has the degree of common metal (the strength of the cold drawn degreased copper pipe is equivalent to that of the steel pipe with the same wall thickness). It is not easy to corrode and is resistant to high temperature and high pressure. It can be used in various applications. The main material of copper bar is copper. The melting point of copper is as high as 1083 ℃, and the temperature of hot water can be ignored for degreased copper pipe, so as long as it is used correctly, there is no need to worry about safety. When choosing to decorate the house, the material of water supply pipeline will greatly affect people's health. T2 copper tube has strong capacity. Escherichia coli in the water supply will not continue to breed in the degreased copper tube, and more than 99% of the water will disappear after entering the degreased copper tube for 5 hours. This biological characteristic is that there is a small amount of copper ions dissolved in water in the degreased copper tube, and copper ions have a strong ability. Copper and zinc plating can avoid rusting and show a zinc protective film to metal materials. The conductive metal material repair and color enhancement care agent I can generate the thickness of the metal material epoxy protection layer and the pipeline cathodic protection layer, which can resist extreme weather and is suitable for the long-term surface of metal materials. The actual effect of salt and water corrosion resistance is good. The copper bar tin plating can prevent the air oxidation of the copper bar and the connection surface of the copper bar. In addition, the melting of metal tin and copper will produce aluminum alloy, the conductivity of metal tin is good. The purpose of copper and tin plating: effectively prevent copper from becoming verdant due to moisture, and also prevent copper from oxidizing/sulfurizing and blackening and affecting electricity. The service life of the tinned copper tube is several times or even more than ten times, which greatly increases the service life of the copper and plays a considerable role in protecting the copper. The of tinned metal surface treatment on copper bar is to avoid air oxidation. As the air in industrial production air, marine climate or cold air is easy to turn black or produce copper green when oxidized, the copper bar surface shall be tinned for the total area, the resistance and conductivity of the steel bar lap surface.With the continuous development of industry, the demand for plastic coated copper tubes is gradually increasing. Then how to apply wood grain paint on alloy pipes. Wood like paint is a kind of wood like paint. It is used for spraying plastic coated copper pipe and its process flow. Plastic coated copper pipe is mainly used to manufacture high-pressure alloy pipe for heating surface of water tube boiler with high pressure and above. In the morning market, the mainstream spot price quoted by Lianzhong was 7900-7950 yuan/ton, and the tax inclusive base price quoted by Hongwang and Chengde was 8070-8150 yuan/ton. On a month on month basis, part of the producing areas recalled 50 yuan, and the mainstream tax inclusive base price in the market changed from strong to weak in the 7900-8100 plastic coated copper pipe supply and demand relationship. It was difficult for the price of plastic coated copper pipe in the Guangzhou market to fall sharply this week. Second plastic coated copper tubes are widely used in superheaters, headers and main steam ducts of domestic HP, UHP and subcritical power plant boilers. Third, large diameter pipes are mainly used as headers and main steam pipes with steam parameters below 565 ℃.

Disadvantages: Due to loose tissue and high pressure resistance, the pipe is only used to produce small air conditioning copper rods.

Now let me talk about the damages that are easy to occur on the surface of the copper tube. In order to prevent the accumulation of process agents or products and/or dirt, scratches and other rough surfaces, mechanical cleaning must be carried out. If the copper pipe is heated to a certain high temperature in the air during welding or grinding, chromium oxide heat return color will appear on both sides, lower surface and bottom of the weld. The color after tempering is thinner than that of the oxidation protective film, and is clearly visible. The color depends on the thickness. The thicker oxide can be found in the rainbow color, blue, purple to brown. It is usually black. It is caused by being at high temperature or being at high temperature for a long time. When any of these oxide layers exist, the chromium content on the metal surface will, and the corrosion resistance of these areas will. In this case, it is not only necessary to heat temper the color and other oxide layers, but also to clean the chromium poor metal layer under it. Free iron on the surface of t2 copper tube will rust causing corrosion of stainless steel. Therefore, the powder that must float can usually be removed together with the dust. Some are very sticky and must be treated as embedded iron. In addition to dust, there are many surface iron sources, including cleaning with ordinary carbon steel wire brush and shot peening with sand, glass beads or other abrasives previously used on ordinary carbon steel, low alloy steel or cast iron, or regrinding non stainless steel products attached to copper pipe components and equipment. If there is no protection during cutting or hoisting, the wire ropes, slings and iron on the working surface can easily be embedded or dirty the surface. The copper tube shall be boiled in boiling water for 30 seconds before cold treatment. The effective internal stress is about 15%, and the residual austenite reaches the effect. Then, the cold treatment can be carried out as usual. Of course, the second suggestion is to choose the normal treatment at minus 60 degrees, and then conduct deep cooling at minus 120 degrees. The lower the treatment temperature is, the retained austenite will be rapidly transformed into martensite, but it cannot be transformed. Through experiments it can be found that there will be about 2% of retained austenite. At this time, retained retained austenite can achieve a certain buffer effect. After cold treatment, the air conditioning copper pipes need to be taken out and put into hot water for heating, which can effectively heat about 40% of the cold treatment stress. Tempering and cold treatment should be carried out as soon as possible after gradual heating, and most of them can avoid cracks as soon as possible, so as to ensure that the products will not deform in later use and facilitate daily storage. The transformation characteristics of the area of each layer of the copper tube during empty drawing affect the asymmetry of the deformation of the metal material. One of its characteristics is that the natural widening of each layer along the wall thickness is not consistent. Of course, the external layer of the copper tube is less, the internal surface layer of the copper tube is larger, and the natural widening of the middle layers is slow from the external layer to the internal surface layer.The technical level of degreasing copper tube for mechanical equipment With the substantial improvement of the manufacturing level of mechanical equipment and the degree of control automation in China, there is still some gap between the technical level of domestic degreasing copper tube production line and the products of foreign counterparts. After years of reform and opening up. The quality of all aspects of degreased copper pipe has also risen by several grades, significantly narrowing the quality gap with the imported production line. The aluminum hose production line and aluminum can production line developed and produced by the company break the technological monopoly of foreign companies, can provide stable and reliable production equipment for domestic and international markets, and make great contributions to the aluminum packaging industry. With the continuous improvement of people's living standards, there will be more and more demand for degreased copper tube products, and its market potential is huge. Problems such as incomplete penetration, deformation, cracks and air holes are easy to occur during the fusion welding of degreased copper tubes. Compared with fusion welding, wood is not melted during brazing, which reduces the impact of large thermal conductivity of base metal on welding quality, prevents the formation of incomplete penetration reduces the tendency to produce pores and cracks, and ensures the performance of weld. Because the base metal is not melted, the structure and properties of the base metal are almost unchanged, so that the original service properties of the base metal can be maintained.

Total quality assurance.The selection of medical copper tube table, these problems are natural.

The price can be changed, the morning market transaction did not follow the temperature rise: after 9:00, the dealers took turns to raise the price, which was in disorder; Before ten o'clock, it was not as expected, and users were very cautious in purchasing; Around 11:00, the surrounding markets became loose and the price was low. High hanging, low selling, and low volume. The market transaction is carried out in such a trilogy, which is different from the opening. In this process, the mentality of traders has changed: from &turning to shipping&, after all it has promoted the steel mill to sell before entering their own mouth? This is a &manic& market again: failed to continue to rise, spot prices rose; The construction site plan is not much, and the market transaction is weak - this week's trading days, the spot price rose, and the transaction was less than expected. As of noon, the sales volume of large inventory customers was hundreds of tons, and the shipment was not much. Judging from the transaction in the morning, the selling price of leading resources rose generally. Among the resources in Kuti, the base price of t2 copper tube was 5050 yuan/ton, and the price of earthquake resistant spiral snail was 5350 yuan; Among the resources provided by the factory, the basic price of threads of Zhongtian, Yonggang and Shagang is 5130 yuan, and the differential between spiral and t2 copper pipes is 360-380 yuan/ton. In terms of the market, the leading market Tangshan narrow band mainstream fell by 30-120 in the early opening. The overall trading situation of copper bars was weak. Some small factories cut prices significantly, and the low price trading was acceptable. Limited production continues, market resources are average, weak market, and downstream procurement is cautious. 355 is the consolidation of the medium broadband market. Today's futures continue to fluctuate. Traders are less willing to ship at low prices and have a strong mood. However, under the pressure of futures, the trading atmosphere in the spot market is not good. Copper bars continued to fluctuate in the morning, we know that there are few high market transactions, few inquiry calls, and a slightly pessimistic attitude. The overall market transaction atmosphere is light, and most merchants operate on the market. At present, the demand for terminal replenishment is low, and the purchasing enthusiasm is not high. According to traders' feedback, the current market is in a weak situation of supply and demand. Downstream feedback shows that many projects are shut down and there is a great pressure on funds. However, the relevant economic data and side news are too bearish, so the futures market is difficult to rebound, and the spot market is mainly responsible for the subsequent drop. However, some traders are still willing to maintain their prices, which is mainly due to the high price of post settlement resources and the low inventory at present. The invention relates to a manufacturing method for a double seal socket flexible connection structure of a large diameter spiral welded steel pipe.

The selection of medical copper tube table, these problems are natural.

However, it may cause recoverable temporary damage to people who have been away from these radioactive sources for a long time. The DC brushless motor with small volume and large power is adopted, which can operate without fault for a long time even if it is opened or closed. Target There will be no sharp decline in the price of copper tubes in Linyi at the end of the month. The price of plastic coated copper pipe will continue. Pop up the position line and line, select PVD chromium nitride ring and molybdenum spraying ring as the matching materials for the plastic coated copper pipe, adhere to the wear form condition simulation criteria of the sample test, use the self-developed opposed reciprocating wear tester, carry out the load level test, wear test, lean oil test, and research the load. As for the corrugated process of the finished plastic coated copper pipe as claimed in claim 1, the radiation source for the engineering design of the integrated rigid flexible connection plastic coated copper pipe belongs to the low hazard source. Basically, it will not cause artificial damage. The basic principle of the foundation of the integral rigid flexible connection plastic coated copper pipe sluice discussed the influence of process parameters and heat treatment process on the microstructure, phase distribution and mechanical properties of the alloy, and obtained some important research results. The number of joints of steel pipes and plastic coated copper pipes on the same section shall not exceed 50% of the number of pipes. Before installation the pipe shed shall sweep and clean the hole with drill bit or high-pressure air, and the scum in the hole shall be removed, Ensure the aperture (The hole diameter shall not be less than 127cm, and the hole depth shall meet the requirements to prevent hole plugging. Most of the seamless steel pipes produced now are hot-rolled. Because of the high temperature, and generally the steel plate is used for rolling. In this operation, the detailed thickness of the steel plate shall also be considered. If it is about the harmful elements with relatively low accuracy requirements, plastic coated copper pipes must be required. The pipe shed can be installed, extended section by section, and What does plastic coated copper pipe with a diameter of 1 reflect in life when the weld length is added to 30 for the joint steel pipe of the pipe extension joint? Plastic coated copper pipe can also produce welded pipes with different pipe diameters from billets of the same width. However, it can be compared with straight seam pipes of the same length. The rental production rate is low.

plan.There are also some serious corrosivity, and some fine sand or vegetable oil coating will appear when the plastic coated copper tube packaging materials and packaging are stored according to special requirements. It can adhere to the surface layer and form excellent passivation effect on the surface layer of the plastic coated copper pipe. When cleaning, a cleaning plan is required. The plastic coated copper pipe must transport some raw oil in the industry. The plastic coated copper pipe has good air tightness to ensure no leakage of gasoline and diesel. It is a good transmission pipeline.

T2 copper bar solid - full diameter copper bar is much more widely used than pure iron. Every year, 50% of copper is electrolyzed into pure copper for electrical industry. The red copper mentioned here really needs to be very pure, and the copper content is above 995%. A small amount of impurities, arsenic, aluminum, will greatly reduce the conductivity of copper. Oxygen content in copper (a small amount of oxygen is easily mixed in copper smelting) has a great impact on conductivity. Copper used in electrical industry must generally be oxygen free. In addition, lead, antimony, bismuth and other impurities will prevent copper crystals from combining, causing hot brittleness, and will also affect the processing of pure copper. This kind of pure copper with high purity is generally refined by electrolysis: using impure copper (i.e. crude copper) as anode, pure copper as cathode and copper sulfate solution as electrolyte. When the current passes, the impure copper on the anode will gradually melt, the stress corrosion cracking inside the stainless steel plate will cause the transition film on the surface of the stainless steel plate. Therefore, the surface of plastic coated copper pipe shall be cleaned to a certain extent to ensure its service life. The oil cracking tube circuit breaker must be selected. The fracture of the plastic coated copper pipe shall be kept on a true circle, and the fracture line shall be inclined to the pivot of the plastic coated copper pipe. Too large is the reason for cutting plastic coated copper pipe into flat or oval shape, so moderate energy shall be used when cutting square steel pipe. What matters should be paid attention to when purchasing plastic coated copper tubes.

Makasa.In particular, it is an improved spray type passivation box for t2 copper pipe production line. The installation step of the connection structure 100 between t2 copper pipe and aluminum bar belongs to the improvement of the spray type passivation box structure for t2 copper pipe production line. The passivation solution spray box is set above the side of the passivation solution box, the passivation solution spray box with downward sloping bottom is connected with the inlet of the passivation solution box by the outlet set on the box wall at the bottom of the inclined bottom the inlet of the passivation solution box is located on the box wall above the passivation solution box, the upper side of the passivation solution box is installed with a passivation pump, and the inlet pipe of the passivation pump is connected with the passivation solution box,Makasa316L stainless steel pipe, The outlet pipe of the passivation pump is connected with the upper port of the passivation liquid spray box. With reasonable structure and convenient operation, it is convenient for operators to add passivation liquid to the passivation box, clean colloidal crystals at the bottom of the passivation box, avoid equipment blockage, and improve the surface quality of galvanized steel pipe.

The medical copper tube 6 is superior to the exterior wall hanging plate decorative building materials. It will be affected by microorganisms in the air all year round, accelerating the loss of its service life. 7 If the wall interface is not properly treated, the board surface also needs to be treated with interface mortar, otherwise it will cause local hollowing of the insulation layer. How to protect the medical copper tube during installation? The medical copper pipe shall be installed in strict accordance with the installation requirements, the construction process must be strictly required, and the later maintenance work must be done well. 1 Place it in the rainproof shed, and do not place heavy objects on the surface.

When I need to use more quantity, what are the factors that cause the surface corrosion of copper tubes. Introduce the factors that cause the surface corrosion of copper tubes. Surface pollution: The oil dust, acid, alkali, salt, etc. attached to the surface of the workpiece will be converted into corrosion medium under certain conditions which will react with some components in the stainless steel parts to produce chemical corrosion and rust.