Brinell hardness (HB), Rockwell hardness (HRC) and Vickers hardness (HV) are commonly used.Stage ( & mdash; )Alcadias,× × ～ × × ～ × × ～ × × ～ × × ～ × × ～ × × ～ × × ～ × × ～ × × ～ × × ～ × × ～ × × Standard treatment of steps for preventing oxidation of ~ square tube square tube is a kind of metallic maintenance. The main components are iron and zinc. It is easy to have redox reaction in the air. Once the reaction occurs, many new substances have taken place, and the original characteristics have changed. However, in order to maintain the original relevant characteristics, anti-oxidation treatment is required. The direct reason is to prevent the square tube from reacting with the oxygen in the air, this article makes a relatively standardized treatment on the relevant steps to prevent oxidation of square tubes: the key depends on what kind of antirust paint you use. . If you use epoxy zinc rich or iron rich antirust paint,AlcadiasGalvanized spiral welded pipe manufacturer, you can directly spray fluorocarbon paint on it; if alkyd antirust or red lead is used it shall be cleaned with paint remover and sprayed with epoxy zinc rich or iron rich antirust paint again before fluorocarbon paint can be sprayed.For transportation: water supply, drainage, mud transportation, marine water transportation.Makeni, machinery, steel construction and other projects, shipbuilding, solar power generation support, steel structure engineering, electric products ( pieces)

If the re inspection results are unqualified (including the items whose preliminary inspection results are unqualified and re inspection is not allowed), the supplier can submit them for acceptance one by one; Or re conduct heat treatment (the number of RE heat treatment shall not exceed times), and propose acceptance with a new batch.The advantages of real bending are small reverse, accurate forming, and as long as the roll shape is accurate, pig iron, ferroalloy, cast iron, etc. Steel and pig iron are alloys based on iron square tube and carbon as the main added element, collectively referred to as iron carbon alloy.total cost,C. special performance steel: (a) stainless and acid resistant steel; (b) Heat resistant steel; (c) Electric heating alloy steel; (d) Electrical steel; (e) High manganese wear resistant steel.Cleaning solvent and emulsion can clean the surface of square tube to remove oil grease, dust, agent and similar organic matter, but it can not remove rust, scale, welding, etc. on the surface of square tube, so it is only used as an auxiliary means in production.Square tubes are classified by forming: forged steel; Cast steel; Hot rolled steel; Cold drawn steel.

The difference between hot-dip galvanized square pipe and cold-dip galvanized square pipe is mainly from the following aspects: the appearance of hot-dip galvanized square pipe is slightly rough compared with cold-dip galvanized square pipe; The appearance of cold galvanized square pipe is smooth and bright.technological innovation,Functional index analysis of qb square tube - commonly used are Brinell angle (HB), Rockwell angle (HRC) and Vickers angle (HV) of qb square tube. Angle is a gauge needle to weigh the soft and hard level of metal data. The angle method is rarely used to determine the internal angle in the current life. It uses the metal data surface tested under the fixed load of the indenter with a certain number and shape to determine its angle value according to the level of the object.Shot blasting and sand blasting are widely used in repair and shipbuilding industry. However, whether shot blasting or sand blasting, compressed air is used. Professional square pipe, square rectangular pipe, seamless square pipe, galvanized square pipe, galvanized pipe has high pressure resistance grade, good waterproof performance, fire and high temperature resistance, strong overload capacity, corrosion resistance, radiation protection and long service life. Of course, it is not shot blasting, so it is necessary to use high-speed rotating impeller. In the repair and shipbuilding industry,Alcadias4-inch galvanized pipe, shot blasting (small steel shot) is mostly used in square pipe pretreatment (rust removal before coating); Sand blasting (mineral sand is used in repair and shipbuilding) is mostly used in formed ships or sections to remove the old paint and rust on the square tube and repaint it. In the repair and shipbuilding industry, the main function of shot blasting and sand blasting is to increase the adhesion of square tube coating paint.Due to the increase of square tube production, there are more and more fake and shoddy square tubes in the market. How to distinguish the fake and shoddy square tubes? Let me teach you some points to distinguish the fake and shoddy square tubes.Alcadias,After spraying (throwing) derusting,AlcadiasGalvanized square pipe rectangular pipe, it can not only expand the physical adsorption on the pipe surface, but also enhance the mechanical adhesion between the layer and the pipe surface. Therefore, spray (throwing) derusting is an ideal derusting method for pipelines. Generally speaking, shot blasting (sand) is mainly used for the inner surface treatment of the pipe, and shot blasting (sand) is mainly used for the outer surface treatment of the pipe. Several problems should be paid attention to in derusting by spraying (throwing).The characteristics of square pipe are as follows: the production process of square pipe is simple the production efficiency is high, the cost is low and the development is fast. The strength of spiral square pipe is generally higher than that of straight seam square pipe. It can produce square pipe with larger pipe diameter with narrow blank, and square pipe with different pipe diameter with blank of the same width. However, compared with straight seam pipe of the same length, the weld length is increased by ~, which will be oriented to the whole country for a long time Individuals and enterprises provide all kinds of square tubes square rectangular tubes, seamless square tubes, galvanized square tubes, galvanized tubes, on-site settlement, honest operation, local offices, long-term cooperation, and low production speed. Therefore, most of the smaller square tubes adopt straight seam welding, and most of the large-diameter square tubes adopt spiral welding.The surface of fake and inferior square tubes is easy to produce scabs. There are two reasons: the material of fake and inferior square tubes is uneven and there are many impurities. The guide equipment of fake and shoddy material manufacturers is simple and easy to stick to steel. These impurities are easy to scar after biting the roll.