08/12/2023
Successful Delivery!|Nansteel Guarantees Supply of the World’s Largest LNG Storage Tank
The 270,000 m3 H and F tanks of 9Ni steel for the CNOOC Zhuhai Phase II LNG project supplied by Nansteel were successfully delivered.
Read More
The common problems can be roughly divided into three types: uneven coating, anti-corrosion agent dripping, and anti-corrosion agent bubbling.1. Uneven Coating. The root cause of this problem is the uneven distribution of the corrosion inhibitor on the surface of the steel pipe. Some parts are coated too thickly, while others are coated too thinly or not at all. This results in areas where the coating is applied too thickly exceeding the standard thickness, leading to waste; while areas where the coating is applied too thinly or not at all will have reduced corrosion resistance, causing rust to form.2. Corrosion Insulator Dripping. When corrosion inhibitors solidify on the surface of a steel pipe like water droplets, it is called corrosion inhibitor dripping. This phenomenon often does not directly affect the corrosion resistance and can still ensure that the steel pipe has a certain required corrosion resistance. However, from an aesthetic point of view, steel pipes with corrosion inhibitor dripping look dull and uneven, directly affecting the appearance of the steel pipe.3. Corrosion Insulator Blistering. Air trapped in the corrosion inhibitor causes air bubbles to form in the coating of the steel pipe. These bubbles vary in size depending on the specifications of the steel pipe. The larger bubbles are shaped like the air bubbles on the protective covers of some home appliance remote controls; they will burst if you press down on them with a little force. The foaming phenomenon of corrosion inhibitors not only affects the appearance of steel pipes, making the entire surface of the steel pipe appear rough and uneven, but the breakage of bubbles will also reduce the standard coating thickness, reduce the anti-corrosion ability, and lead to rust in the steel pipe area where the bubbles are located.
Seamless steel pipes have very high strength. Due to the use of high-precision rolling and heat treatment technology in the manufacturing process, seamless steel pipes have uniform wall thickness and no internal gaps, resulting in very high tensile and compressive strength. This high strength enables seamless steel pipes to withstand greater pressure and tension, and they are not easily deformed or broken, thus performing excellently in various complex environments.Secondly, seamless steel pipes are extremely durable. Because it undergoes multiple quality inspections and controls during its manufacturing process, seamless steel pipes have very stable quality and excellent properties such as corrosion resistance, wear resistance, and high temperature resistance. This makes seamless steel pipes have a longer service life than ordinary steel pipes, and they can maintain good performance and appearance even after long-term use.
The strength of seamless steel pipes is mainly due to their unique production process and high-quality raw materials.
Unique manufacturing process: The manufacturing process of seamless steel pipes is complex and meticulous, with no welding seams produced throughout the process. This makes the overall structure of the steel pipe more complete and stable, greatly improving its compressive strength. In addition, through processes such as hot rolling and cold drawing, the material of the steel pipe has been optimized, and its strength and toughness have been significantly improved.High-quality raw materials: Seamless steel pipes are usually made of high-quality steel, which has excellent mechanical properties. By combining the characteristics of seamless steel pipe production technology, the strength and durability of the product can be further improved.
The rust prevention ability of stainless steel wire and galvanized steel wire is not absolutely superior or inferior, but depends on their respective rust prevention mechanisms and suitability for the application environment. The two resist corrosion in different ways, and their rust prevention performance will show significant differences in environments with different humidity and medium concentrations.In terms of rust prevention mechanisms, the core protection logic of the two is fundamentally different. The rust prevention of stainless steel wire relies on the chromium element inside it. When the chromium content reaches more than 10.5%, it will react with oxygen when exposed to air, forming a very thin (about 5-10 nanometers) and dense chromium oxide passivation film on the surface. This film can adhere tightly to the surface of the steel wire, blocking the contact between moisture, oxygen and the substrate. Even if the local film layer is damaged, the surrounding chromium elements can quickly react with oxygen to reform the passivation film, achieving "self-repair" rust prevention. For example, common 304 stainless steel wire (containing 18%-20% chromium) can maintain a stable passivation film for a long time in dry air, with almost no obvious corrosion; even if it comes into contact with a small amount of moisture for a short period of time, it can maintain the anti-rust effect through self-repair.Galvanized steel wire uses the principle of "sacrificial anode protection," which achieves rust prevention by electroplating or hot-dip immersion of a zinc layer on the surface of the steel wire. Zinc is more chemically reactive than iron. When steel wire is exposed to a corrosive environment, zinc will preferentially undergo oxidation reaction before the base iron (i.e., "sacrifice" the zinc layer), thus protecting the internal steel wire from corrosion. Simultaneously, the zinc oxide and zinc hydroxide products formed after zinc oxidation create a loose but somewhat barrier-like protective layer on the surface, further slowing down corrosion. For example, the zinc layer of hot-dip galvanized steel wire can be 80-120 micrometers thick. In dry or slightly humid environments, the zinc layer can be slowly consumed, providing the steel wire with rust protection for several years or even more than a decade.Environmental factors are the key variables that determine the rust-preventive effect of both. Both exhibit good rust prevention capabilities in neutral and dry environments (such as dry indoor areas or factories without corrosive dust). Stainless steel wire has a stable passivation film, and its surface can remain bright even after long-term use; the zinc layer of galvanized steel wire is consumed slowly and is not prone to obvious rust. At this point, the difference in rust prevention between the two is not significant, and the choice can be made based on cost and appearance requirements.
China Steel Market
Empowering small and medium-scale steel purchasing
Hot search words:
China Rebar prices China Wire Rod Prices