Effective treatment of square tube coating & ldquo; Surface defense line & rdquo; Surface technology and measures square tube coating is used as the back course & ldquo; Surface defense line & rdquo; The surface treatment technologies and measures can be carried out on the basis of other surface treatment technologies or processes. Heres the & ldquo; Surface treatment before coating & rdquo; It refers to all treatment measures for preparation for coating or joint protection with coating. Therefore， the surface treatment before coating is also called coating surface pretreatment.
7Therefore， QA is usually not preheated. However， when the plate is very thick， it should be preheated because it cools quickly. Once # steel was cracked by J welding. If the plate thickness is more than mm， there is a great risk of not preheating.
tIt is good to purchase Baosteels materials for cold drawing of square tubes，Galvanized pipe because Baosteels materials are subject to grade flaw detection，20 galvanized pipeCommon problems and troubleshooting and the density of steel is relatively good. After cold drawing and heating， it is convenient to line up. The steel is cold drawn at room temperature to produce plastic deformation， so as to improve the yield strength. This process is called cold drawing strengthening. Square tube is generally used for product parts with high requirements. It has good willfulness and strength. The surface is better after cold drawing. Cold drawing principle.
After the square pipe is produced the surface treatment is generally carried out， that is， rust， dirt and attachments on the surface of the square pipe are removed. Those that cannot be treated by physical treatment should be treated by chemical treatment.
JNicastroThe qb square tube protective layer thickness detector is used to measure the actual thickness of the seamless qb square tube protective layer on site. It is required that the actual thickness of the seamless qb square tube protective layer of the seamless qb square tube shall not be lower than the design value. When the requirements are not met， the protective layer of seamless qb square tube can be chiseled and measured.
WgOn the basis of thermodynamic calculation， the quality assurance of square tube， rectangular tube，Galvanized pipe seamless square tube， galvanized square tube and galvanized tube is professional. New and old customers are welcome to consult during the preferential activities. The process conditions of calcium treatment of CrMo sulfur-containing square tube are analyzed， and the sulfur-containing gear rolled products after calcium treatment are sampled and studied. The conclusions are as follows: in order to minimize the generation of Cao in sulfur-containing square tube steel， Omega in molten steel; (O) It must be taken off to & times; The rate of calcium can only be guaranteed below -.
As a bridge; Pipes for wharf road， building structure， etc. It is mainly used as petroleum geological drilling pipe， cracking pipe for petrochemical industry， boiler pipe， bearing pipe， high-precision structural pipe for automobile，Galvanized pipe tractor and aviation， etc.
In the process of square pipe，20 galvanized pipeCommon problems and troubleshooting we will conduct a variety of tests on it to ensure that the square pipe can be better used in practice. In order to make better use of large-diameter steel pipe， we will continue to innovate. Lets introduce the main elements contained in the lower pipe. For the martensitic chromium square tube， the main elements affecting the are chromium， carbon and molybdenum; For Martensitic chromium nickel square tube， molybdenum， aluminum， cobalt， nitrogen and titanium.
jStrength refers to the performance of metal materials under static load (excessive plastic deformation or fracture). Since the action modes of load include tension，Galvanized pipe_ Galvanized square pipe_ Seamless steel pipe_ Square tube - Wuxi Jiahang compression， bending and shear， the strength is also divided into tensile strength， compressive strength， flexural strength and shear strength. There is often a certain between various strengths. Generally， tensile strength is used as the basic strength indicator. Appropriate sites and warehouses shall be selected. The sites or warehouses for storing steel pipes shall be in clean and unobstructed places， away from factories and mines that produce harmful gas or dust. Weeds and sundries shall be removed on the site to keep the steel pipe clean; In the warehouse， it is not allowed to stack with acid， alkali salt， cement and other materials that are corrosive to the steel pipe. Different types of steel pipes shall be stacked separately to prevent confusion and corrosion; Large section steel， rail， steel plate， large-diameter steel pipe， forging， etc. can be stacked in the open air; Small and medium-sized section steel， wire rod， reinforcement， medium diameter steel pipe， steel wire and steel wire rope can be stored in a well ventilated shed， but they must be covered and padded; Some small steel pipes， steel sheets， steel strips， silicon steel sheets， or thin-walled steel pipes， all kinds of cold-rolled and cold drawn steel pipes and high and corrosive metal products can be stored in the warehouse; The warehouse shall be selected according to geographical conditions， and generally adopts ordinary closed warehouse， that is， the warehouse with roof， enclosure， tight doors and windows and ventilation devices; The warehouse is required to pay attention to ventilation in sunny days close and damp proof in rainy days， and often maintain a suitable storage environment. The principle of reasonable stacking and first in first stacking is to stack according to varieties and specifications under the condition of stable stacking and ensuring safety. Materials of different varieties shall be stacked separately to prevent confusion and mutual corrosion; It is forbidden to store articles that have corrosive effect on steel pipes near the stacking position; The bottom of the stack shall be padded high， firm and flat to prevent the material from moisture or deformation; The same kind of materials shall be stacked according to the warehousing order， so as to facilitate the implementation of the principle of first in， first out; The section steel stacked in the open air must be provided with wooden mats or strip stones. The stacking surface is slightly inclined to facilitate drainage. Pay attention to the straightness of the material placement to prevent bending and deformation; The stacking height shall not exceed m for manual operation， m for mechanical operation and m for stacking width; A fixed channel shall be reserved between stacks， generally .m and the access channel is generally ~ om depending on the size of materials and transportation machinery; The bottom of the stack shall be padded up. If the warehouse is cement floor， it can be padded up by .M; If it is muddy ground， it must be padded . ~ .m high. If it is an open site， . ~ . m higher than the sand and mud surface， the angle steel and channel steel shall be stacked in the open air， i.e. the mouth shall face down， and the I-beam shall be placed vertically. The i-groove surface of the steel pipe shall not face up to avoid ponding and rust. The packaging and protective layer of the protective materials shall be coated with agent or other plating and packaging before leaving the factory， which is an important measure to prevent material corrosion. Attention shall be paid to protection during transportation， loading and unloading and shall not be damaged， The storage period of materials can be extended， the warehouse shall be kept clean and the maintenance of materials shall be strengthened. Before warehousing， such as steel wire brush for high hardness and cloth， cotton and other materials for low hardness; The materials shall be regularly after warehousing. If there is corrosion， the corrosion layer shall be removed; Generally， but for high-quality steel， alloy steel sheet， thin-walled pipe， alloy steel pipe， etc.， the internal and external surfaces need to be coated with anti rust oil before storage; Steel pipes with serious corrosion shall not be kept for a long time after rust removal and shall be used as soon as possible. With the development of economy， all kinds of square tubes， rectangular tubes， seamless square tubes， galvanized square tubes， galvanized square tubes have been sold at high prices throughout the country for a long time. The reasonable price and perfect service of galvanized tubes have been recognized by the majority of customers. There are more and more fake products in the market. In order to prevent yourself from being deceived when you are in square tubes， you need to know some knowledge about how to judge the authenticity of square tubes: & ldquo; We can judge by observing the surface and flatness of the square tube
PFunctional index analysis of square tube - angular plasticity refers to the power of plastic deformation (permanent deformation) without destruction of square tube data under load.
SconsumptionThe banding caused by component segregation is difficult to be eliminated by heat treatment. Generally， normalizing can reduce this segregation to a certain extent. Generally normalizing can correct the segregation to the allowable level. If the banding is serious， it can be improved by multiple normalizing. It is reliable to conduct high-temperature diffusion annealing first and then normalize again， which can completely eliminate the strip， but the cost will be very high， which is difficult to achieve for the steel plate due to the surface quality.
aNWhen cutting the sample， the surface of the sample shall not be damaged， the properties of the metal shall not be changed due to heating or cold processing， and the edges at the section shall be rounded.
Drawing process flow of square tube in the production process of square tube， it needs a lot of processes to complete the production process， so that the production quality of square tube can be more strictly guaranteed. This paper mainly introduces the drawing process flow of square tube. Lets understand it below.
Various treatments are summarized as follows: high temperature oxidation method is to immerse the workpiece in a specific molten salt and maintain a fixed process temperature and time
rankingxSquare pipes are mainly used in engineering buildings， glass curtain walls， guardrails steel structures， machinery， automobiles， household appliances， shipbuilding， containers， agricultural construction， agricultural greenhouses， bicycle frames， motorcycle frames， shelves， fitness equipment， leisure and tourism， steel furniture， various specifications of oil casing， oil pipes and pipeline pipes， water， gas， sewage， air Heating and other fluid transportation， fire fighting and support， construction and other fields.
SAfter cold drawing and aging treatment， the yield point is improved the tensile ultimate strength is also increased， and the plasticity continues to decrease. Due to the reduction of internal stress during aging， the modulus can be basically restored. According to this principle， cold drawing or cold drawing of reinforcement or low carbon steel wire rod is often carried out on site or prefabricated component factory， so as to improve yield strength and save steel.
The modification of Ca， rare earth and other trace elements on inclusions changes the structure， morphology and physical properties of inclusions in steel， spheroidize and refine inclusions in steel， so as to improve the mechanical properties of square tubes.
kThe square tube will be tested in many aspects of its performance in the process. Each test is for the square tube to have a good performance in practical application. So what are the different properties of square tubes? Next， such as warehouses， houses and bridges， but it is not suitable for moving components such as wheels. At this time， people often use the plastic theory. The research of the plastic theory can be traced back to . In ， the European Design Association formulated D plastic design code， which is mainly used for plane beams under static load and bending stress For the frame structure with stress， the requirements are as follows:% sigma; B% sigma;% zeta;% ge;% delta;% ge; % for high-rise buildings， more detailed calculation is required. In the case of plastic design， the allowable stress is usually calculated according to the safety factor that the allowable stress is not less than the dynamic load and multiplied by the allowable stress. In the case of bending of an axis， the formula a = w can be used Using plasticity instead of calculated strength can improve the bearing capacity of members by %.
Square pipe， the steel pipe whose ratio of outer diameter to wall thickness is less than is called square pipe. At present， the square tubes produced by qb square tube factory are mainly used in tap water engineering， petrochemical industry， chemical industry， electric power industry， agricultural irrigation and urban construction. For transportation: water supply and drainage. For gas transmission: gas