Human factors are also one of the causes of product oxidation that some consumers often encounter when using stainless steel products. Some consumers operate improperly in product use and maintenance,The former Yugoslav Republic of MacedoniaSpecification of stainless steel square pipe, especially some stainless steel pipe products used in food and chemical equipment industry. For the artificially generated oxidation of steel products, they should have correct product use knowledge and Reasonable and effective maintenance shall be carried out regularly to reduce oxidation caused by improper use.Stainless steel pipe packing bag is nothing more than the function of protecting the surface of stainless steel pipe, so most stainless steel pipe users do not have to question this point.The former Yugoslav Republic of Macedonia,Stainless steel pipes are divided into hot rolled, hot drawn and cold drawn (rolled) stainless steel pipes according to the connection and rolling process. According to the difference of stainless steel microstructure, they mainly include semi Ferritic and semi martensitic stainless steel pipes, martensitic stainless steel pipes, austenitic stainless steel pipes, austenitic ferritic stainless steel pipes, etc.Stainless steel seamless steel pipe for structure (instead of gbt-)Safi,Ferritic stainless steel the Cr content of ferritic stainless steel is generally % ~ %, and the carbon content is less than .%. Other alloying elements are sometimes added. The metallographic structure is mainly ferrite, and there is no & alpha during heating and cooling=& amp; amp; gt;& gamma; The transformation cannot be strengthened by heat treatment. Strong oxidation resistance. At the same time, it also has good hot workability and certain cold workability. Ferritic stainless steel is mainly used to make components with high corrosion resistance and low strength requirements. It is widely used in manufacturing equipment such as production, nitrogen fertilizer and chemical pipelines.Application fields: chemical industry, construction industry.After that, the second widely used steel is mainly used in food industry, pharmaceutical industry and surgical equipment. Adding molybdenum makes it obtain a special corrosion-resistant structure. Because it has better chloride corrosion resistance than stainless steel pipe, whether it is data consumption or price. However the proportion of water pipes is very small, once the water pipes show achievements, the results will be very serious. Therefore, it is extremely important to choose water pipes with reliable quality, high volatility, convenient maintenance, health and environmental protection. With the development of the national economy and the progress of people's living standards, people's requirements for domestic water pay more and more attention to health and environmental protection. A good water source escort pipeline has become a careful choice. Water pipes are generally experienced in lead pipes & rarr; Copper pipe & rarr; Iron pipe & rarr; Galvanized iron pipe → Plastic pipe & rarr; Development process of stainless steel pipe. It has become a trend in the world to select high-quality stainless steel materials as water supply pipes. The material indicates that in Germany, more than % of residents choose stainless steel water pipes; In Japan, more than % of households in Tokyo have adopted stainless steel water pipes; In Australia, it has begun to change other pipes to stainless steel pipes; In the United States, the water pipes of five-star hotels in Las Vegas are all made of stainless steel. Since the beginning of the st century, due to the progress of living standards, more than % of residents in China need water pipes to meet their needs of high-quality life. Therefore, high-quality stainless steel materials move from tableware to household water pipes. It has become a trend to select high-quality stainless steel pipes in tooling or home decoration projects. Stainless steel water pipes and stainless steel pipe fittings will become an indispensable part of the building materials market in the future. Stainless steel material is a recognized health material that can be implanted. The manufacture of water pipes based on stainless steel has a long history in developed countries. Stainless steel pipe has gradually become a new choice of water supply pipe with the characteristics of safety, sanitation, environmental protection, economy and applicability, and has become the current world trend and development direction. Stainless steel water pipe is called the real green pipe in the st century. With the gradual standardization of stainless steel pipe industry, it can be predicted that the consumption technology and connection technology of stainless steel pipe will also slow down to standardization and become more and more perfect. The development of stainless steel pipe technology will not only create a favorable condition for health, environmental protection and sanitation for national domestic water, but also win a larger market for stainless steel pipe enterprises. Stainless steel pipe entering the construction and decoration market is an attack in the water pipe industry.Stainless steel pipe will not rust, but it is relatively not easy to rust. It will rust in a specific environment. It will rust if placed in seawater or acid-base environment. Even in the air, it will be corroded and oxidized slowly, but it will take a long time. In general, stainless steel pipes will not rust. However, if the stainless steel pipe is used or maintained improperly, or the environment in which the stainless steel pipe is located is too bad, the stainless steel pipe may rust. When we see rust spots on the steel surface, we can quickly confirm that it is a sign of rust. Why does stainless steel pipe rust? First of all, let's understand the structure of stainless steel pipe: stainless steel pipe is a crystal solid composed of atoms similar to a piece of toys. In addition to iron it also contains its metal components, such as chromium, nickel titanium, etc. Chromium and nickel have anti rust function. It forms a protective film - passive film to prevent stainless steel pipe from rusting. Generally, as long as the film is not damaged, broken or contaminated by impurities, the stainless steel pipe will not rust. However, the stainless steel pipe will rust.Hardness test: annealed stainless steel pipes with inner diameter of more than mm and wall thickness of less than mm can be tested by w-b Vickers hardness tester, which is very fast and simple, and is suitable for rapid and nondestructive qualification test of stainless steel pipes. For stainless steel pipes with inner diameter of more than mm and wall thickness of more than mm,The former Yugoslav Republic of MacedoniaStainless steel pipe threading, Rockwell hardness tester shall be used to test HRC hardness. Stainless steel pipes For stainless steel pipes with inner diameter greater than mm and wall thickness less than mm, the surface Rockwell hardness tester shall be used to test HRT or hrn hardness. For stainless steel pipes with inner diameter less than mm and greater than mm,The former Yugoslav Republic of MacedoniaStainless steel braided belt, the Rockwell or surface Rockwell hardness tester can also be used to test the hardness of pipes.Quality management,First of all, let's understand what stainless steel is. Generally speaking, steel that will not rust is called stainless steel, but in an academic sense, steel resistant to weak corrosive media such as air steam and water and chemical corrosive media such as acid, alkali and salt. Also known as stainless acid resistant steel. In practical application, the steel resistant to weak corrosion medium is often called stainless steel, while the steel resistant to chemical medium is called acid resistant steel. Due to the difference in chemical composition between the two, the former is not necessarily resistant to chemical medium corrosion, while the latter is generally stainless. The corrosion resistance of stainless steel depends on the alloying elements contained in the steel. Chromium is the basic element for stainless steel to obtain corrosion resistance. When the chromium content in the steel reaches about %, chromium reacts with oxygen in the corrosive medium to form a thin oxide film (self passivation film) on the steel surface, the commonly used alloy elements include nickel, molybdenum, titanium, niobium, copper, nitrogen, etc., so as to meet the requirements of various uses on the microstructure and properties of stainless steel.The corrosion resistance of stainless steel depends on chromium, the protection is different. Series & mdash; martensitic precipitation hardening stainless steel pipe.
When using this method, it should be noted that the water-soluble paper should be double-layer and must be pasted well, otherwise it is easy to cause damage and fall off of the water-soluble paper, resulting in loss of argon protection of the inner weld and oxidation, resulting in cutting of the weld junction and re welding, which can not ensure the welding quality and seriously affect the construction period. Therefore the water-soluble paper should be strictly checked and pasted before welding.details,Deformation strengthening of austenitic stainless steel stainless steel has good cold deformation performance. It can be cold drawn into very thin steel wire and cold rolled into very thin steel strip or steel pipe. After a large amount of deformation, the strength of the steel is greatly improved, especially when rolling in the subzero temperature zone. The tensile strength can reach more than MPa. This is because in addition to the cold hardening effect, there are also superimposed Deformation induced M transition.Basic weight (density) / kg of steel plate: SPCC & mdash& mdash; Cold rolled carbon steel sheet and strip are generally used, add t at the end of the brand as spcct.When hoisting stainless steel pipes, public slings, such as hoisting belt and public collet number, shall be used. It is strictly prohibited to use steel wire rope to avoid scratching the surface; and when hoisting and placing, it shall prevent scratching caused by impact and collision. If there are surface scratches, electric arc traces and surface purification in the process of transportation, storage and processing, it must be completely cleaned polished with an angle grinder, and then polished Polishing with optical sheet or metallographic sandpaper.The former Yugoslav Republic of Macedonia,At present, and the total surface grinding yield has reached %. In order to achieve this goal, it is necessary to refine the molten steel, achieve low oxygen and sulfur content, do a good job in the metallurgy of the ladle and tundish, accurately determine the molten steel temperature, and realize no oxidation casting, Further reduce the inclusion content.