We all know that the general steel structure project needs to use a large number of steel structure parts, but the steel structure parts can not be completely used in a short time.It is easy to cause rust of steel structure.A large number of steel used in construction will greatly shorten the service life.It is also a challenge to personal safety. The collapse of buildings is common, and more and more attention has been paid in recent years. Therefore, the rust removal of steel structure parts can not be ignored.Today, 3D steel structure company will teach you some rust removal methods for steel structure! 　　

 1、 There are several types of derusting methods for steel members in steel structure company 　　

 Five common methods of rust removal on steel structure surface 　　

 There are four methods to remove rust on steel structure metal surface: manual treatment, mechanical treatment, chemical treatment and flame treatment.

(1) Manual processing:　

 Manual treatment mainly uses shovel, wire brush, emery cloth, broken steel saw blade and other tools to remove rust by hand tapping, shoveling, scraping, brushing and sand. This is the traditional method of rust removal for painters, and it is also a very simple method. There is no restriction of any environment and construction conditions. However, due to the poor efficiency and effect, it can only be applied to a small range of rust removal. 

(2) Mechanical derusting 　　

 Mechanical derusting method mainly uses some electric and pneumatic tools to remove rust.Common electric tools such as electric brush and electric grinding wheel; pneumatic tools such as pneumatic brush.Electric brush and pneumatic brush use the rotation of special round steel wire brush to remove rust or oxide scale by impact and friction. Especially for surface rust, the effect is good, but it is difficult to remove deep rust spots.The electric grinding wheel is actually a hand-held grinder, which can be moved freely in the hand, and the high-speed rotation of the grinding wheel is used to remove rust. Especially for deep rust spots, its work efficiency is high, the construction quality is good, and the use is convenient. It is an ideal derusting tool.However, attention should be paid not to pierce the metal skin during operation.

(3) Sand blasting and shot peening　　

 The sand blasting and shot peening are the same as the previous method of removing the old film. 

Shot blasting derusting machine commonly used in steel structure company

(4) The flame treatment method is to use the gas welding gun to burn a small amount of deep rust spots which are difficult to remove by hand, so that the high temperature can change the chemical composition of the rust oxide and achieve the purpose of rust removal.When using this method, attention should be paid not to burn through the metal surface and to prevent large area surface from thermal deformation.

(5) Chemical treatment 　　

 The chemical treatment method is actually acid pickling rust removal method. The acid solution reacts with metal oxide (rust) to form salts and leave the metal surface.Common acid solutions are sulfuric acid, hydrochloric acid, nitric acid and phosphoric acid.In operation, the acid solution is applied to the rusty parts of the metal, and the rust is removed by chemical reaction.Wipe and dry the solution, and then wash it with water to prevent rust.　　

 The acid washed metal surface must be rough treated or phosphated, mainly to increase the adhesion between the metal surface and the primer.　　

 When diluting the concentrated sulfuric acid, pour the sulfuric acid into the water in the container slowly and stir it continuously. Do not operate in the opposite direction, so as to avoid hurting people by splashing out the sulfuric acid liquid.

 2、 The steel structure rust removal method was introduced before, so how to identify the steel structure rust removal in the end?The following by the three-dimensional steel structure for you to introduce: steel structure surface derusting grade standards are as follows

 　　(1) The standard of steel structure surface rust and derusting grade is gb8923-88 “rust grades and derusting grades of steel surface before coating”. 　　

 　　(2) According to the standard, the derusting grade is divided into three types: spray or blast derusting, manual and electric derusting and flame derusting. 

Standard steel member display after derusting of steel structure

　　(3) Spray and blast rust removal, denoted by the letter “Sa”, is divided into four grades: 　　

 　　(4) The standard of steel structure surface rust and derusting grade is gb8923-88 “rust grades and derusting grades of steel surface before coating”.

 3、 According to the standard, the derusting grade is divided into three types: spray or blast derusting, manual and electric derusting and flame derusting. 　　

 　　(1) Spray and blast rust removal, denoted by the letter “Sa”, is divided into four grades: 　　

 　　SA1 – slight spray rust removal after spraying.The steel surface shall be free of visible grease, dirt, loose oxide scale, rust, paint coating and other attachments. 　　

 　　SA2 – thorough spray or spray rust removal.There is no visible grease and dirt on the steel surface, and the attachments such as oxide scale and rust are basically removed. 　　

 　　Sa21 / 2 – very thorough rust removal by spraying or jetting.There is no visible grease, dirt, oxide scale, rust, paint coating and other attachments on the steel surface, and any residual traces are only spot or strip-shaped light spots. 　　

 　　SA3 — spray or spray derusting to make the surface of steel structure very clean.There is no visible grease, dirt, oxide scale, rust, paint coating and other attachments on the steel surface, and the surface shows uniform metal color.