The strength, plasticity and angle discussed later are the machine function indicators of metal under static load. In practice, many mechanical machines are under repeated load, and the whole opportunity is tired in this environment.Pig iron refers to the product made by smelting iron ore in blast furnace. It is mainly used for steelmaking and square casting. Put the cast pig iron in the melting furnace to obtain cast iron (liquid), and cast the liquid cast iron into a cast square pipe. This kind of cast iron is called cast iron.Lhasa Lude,When the square tube is covered, the surface of the square tube shall be ventilated to avoid the collection of water vapor on the surface due to difficult volatilization.The pipeline is only subject to chemical pickling which can remove oxide scale, its anchor lines are shallow and easy to pollute the surrounding environment. The square tube shall be submitted for acceptance in batches rust and old coating. Sometimes it can be used as the reprocessing after sand blasting. Although chemical cleaning can make the surface reach a certain cleanliness and roughness, and the batch rules shall comply with the provisions of corresponding product standards.Nagoya City,Stage ( & mdash; )Stage ( & mdash; )Pull square tube:

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,Lhasa LudeSC galvanized pipe, seamless square tubes, galvanized square tubes,Lhasa LudeHot dip galvanized square pipe, galvanized tubes, 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.It seems that preheating the qb square tube can avoid a lot of problems, and there will be a better guarantee that the qb square tube itself is a quality problem.Superior square tubular steel (both P and s ≤ .%)Honest service,Impact toughness the load acting on the machine part at a great speed by QB is called impact load, and the ability of metal under impact load is called impact toughness.Empty bending empty bending is the bending moment formed in one direction between the outer roll and the outer wall of the tube blank to bend the strip. Empty bending will compress the bending line, and the metal at the bending will accumulate and thicken, which is the compression thickening effect of empty bending.The reason why it is divided into two types is that chemical cleaning can only clean the surface very thoroughly, and it is difficult to achieve the desired results in some fine cracks.

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.assets,The square tube is divided into a. boiling steel according to the degree of deoxidation and pouring; b. Semi killed steel; c. Killed steel; d. Special killed steel. The deformation of qb square tube is mainly caused by the shrinkage force of the weld greater than the strength of the base metal.Shot blasting is a high-speed rotating impeller that throws small steel shot or small iron shot out and hits the surface of the square tube at high speed, so the oxide layer on the surface of the square tube can be removed. At the same time, the steel shot or iron shot impacts the surface of the square tube at high speed, resulting in lattice distortion and deformation on the surface of the square tube, increasing the surface hardness, which is the main reason for the surface deformation of the square tubeFunctional index analysis of qb square tube - the load on the machine parts due to the great progress of strength is called the frontal collapse load. The power of destruction of qb square tube under the frontal collapse load is called the frontal collapse toughness.Lhasa Lude,After spraying (throwing) derusting 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).Square tube production most square tube processing is square tube pressure processing, resulting in plastic deformation of the processed steel (billet, ingot,Lhasa LudeQ235A galvanized pipe, etc.). According to the square tube processing temperature, the square tube can be divided into cold processing and hot processing. The main processing of square tube includes: rolling: the gap (various shapes) between the square tube metal blank and the rotating roll , the material section is reduced and the length is increased. This is a common production method for producing square tubes. It is mainly used to produce square tube profiles, plates and tubes. It is divided into cold rolling and hot rolling.In this period, the technology of continuous rolling pipe was not mature.