ZG35Cr24Ni7SiN pipe with Final quality

Description

ZG35Cr24Ni7SiN pipe is a high-chromium-nickel austenitic stainless steel, which has excellent corrosion resistance in oxidizing media and good High temperature mechanical properties, so it can be used for both corrosion-resistant and high-temperature parts. (typical composition%: 0.35C, 0.15Si, 0.95Mn, 0.025P, 0.006S, 23Cr, 6Ni) .

ZG35Cr25Ni20Si2 has better oxidation resistance than 0Cr23Ni13. In fact, it is mostly used as heat-resistant steel for the manufacture of high-temperature furnace tubes for hydrogen stripping. Oxidation-resistant steels, furnace parts, nozzles, combustion chambers that withstand repeated heating below 1000 degrees Celsius. Under high temperature conditions, steels with oxidation resistance, sufficient high temperature strength and good heat resistance are called heat-resistant steels. ZG35Cr24Ni7SiN heat-resistant stainless steel, domestic brand ZG35Cr24Ni7SiN American brand equivalent to S32750

Heat treatment specifications: solid solution 1040 ~ 1180 ℃ rapid cooling. Phase structure: The structure is characterized by austenitic type.

Delivery status: Generally, it is delivered in a heat-treated state, and the type of heat treatment is indicated in the contract; if it is not indicated, it will be delivered in a non-heat-treated state. Smelting Heat-resistant steels are generally smelted in electric arc furnaces or induction furnaces. Those with high quality requirements often use vacuum refining and out-of-furnace refining processes. Casting Some high-alloy heat-resistant steels are difficult to process and deform, and the production of castings is not only more cost-effective than rolling materials, but also has higher lasting strength. Therefore, heat-resistant cast steel occupies a considerable proportion in heat-resistant steel. In addition to sand casting, the casting method can also use precision casting to obtain products with smooth surfaces and accurate dimensions. Centrifugal casting is often used for high-temperature furnace tubes used for synthetic ammonia and ethylene cracking. Heat-treated pearlitic heat-strength steel is usually used after normalizing or quenching and tempering; martensitic heat-resistant steel is quenched and tempered to stabilize the structure and obtain good comprehensive mechanical properties and high-temperature strength. Ferritic steels cannot be strengthened by heat treatment. In order to eliminate the internal stress caused by cold plastic deformation processing and welding, annealing treatment can be carried out at 650-830 ° C, and then rapidly cooled after annealing, so as to quickly pass through the brittle temperature range of 475 ° C. Most of the austenitic oxidation-resistant steels adopt high-temperature solid solution. Heat treated to obtain good cold deformability. Austenitic hot-strength steel is first treated by high-temperature solution treatment, and then subjected to aging treatment at a temperature of 60-100 °C higher than the operating temperature to stabilize the structure and precipitate the second phase to strengthen the matrix. Heat-resistant cast steels are mostly used in the as-cast state, and some are heat-treated according to the type of heat-resistant steel.

ZG35Cr24Ni7SiN is often used in the manufacture of boilers, steam turbines, power machinery, industrial furnaces, and parts and components that work at high temperatures in industrial sectors such as aviation and petrochemicals. In addition to high temperature strength and high temperature oxidation corrosion resistance, these parts also require sufficient toughness, good workability and weldability, and certain organizational stability according to different applications. China has been producing heat-resistant steel since 1952. In the future, some new low-alloy heat-strength steels were developed, so that the working temperature of pearlite heat-strength steels was increased to 600-620 °C; in addition, some new low-chromium-nickel oxidation-resistant steels were developed. Heat-resistant steel and stainless and acid-resistant steel cross each other in terms of use. Some stainless steels have both heat-resistant steel properties and can be used as both stainless acid-resistant steel and heat-resistant steel. The elements formed by ferrite such as chromium, aluminum and silicon can promote the formation of a dense oxide film on the metal surface at high temperature and prevent continued oxidation. They are the main elements to improve the oxidation resistance and high temperature gas corrosion resistance of steel. However, excessive aluminum and silicon content will seriously deteriorate the room temperature plasticity and thermoplasticity. Chromium can significantly increase the recrystallization temperature of low alloy steel, and when the content is 2%, the strengthening effect is good. Nickel and manganese can form and stabilize austenite. Nickel increases the high temperature strength of austenitic steels and improves carburization resistance. Although manganese can replace nickel to form austenite, it damages the oxidation resistance of heat-resistant steel. Vanadium, titanium and niobium are strong carbide forming elements, which can form fine and dispersed carbides and improve the high temperature strength of steel. The combination of titanium and niobium with carbon also prevents intergranular corrosion of austenitic steels at high temperatures or after welding. Carbon and nitrogen can expand and stabilize austenite, thereby increasing the high temperature strength of heat-resistant steel. When the steel contains more chromium and manganese, the solubility of nitrogen can be significantly improved, and nitrogen alloying can be used to replace the more expensive nickel.

Boron and rare earth are trace elements in heat-resistant steel. Boron dissolves into the solid solution to distort the crystal lattice, and the boron on the grain boundary can prevent element diffusion and grain boundary migration, thereby improving the high temperature strength of steel; rare earth elements can significantly improve the oxidation resistance of steel and improve thermoplasticity.

The elements formed by ferrite such as chromium, aluminum and silicon can promote the formation of a dense oxide film on the metal surface at high temperature and prevent continued oxidation. They are the main elements to improve the oxidation resistance and high temperature gas corrosion resistance of steel. However, excessive aluminum and silicon content will seriously deteriorate the room temperature plasticity and thermoplasticity. Chromium can significantly increase the recrystallization temperature of low alloy steel, and when the content is 2%, the strengthening effect is good.

Nickel and manganese can form and stabilize austenite. Nickel increases the high temperature strength of austenitic steels and improves carburization resistance. Although manganese can replace nickel to form austenite, it damages the oxidation resistance of heat-resistant steel.

Vanadium, titanium and niobium are strong carbide forming elements, which can form fine and dispersed carbides and improve the high temperature strength of steel. The combination of titanium and niobium with carbon also prevents intergranular corrosion of austenitic steels at high temperatures or after welding.

Carbon and nitrogen can expand and stabilize austenite, thereby increasing the high temperature strength of heat-resistant steel. When the steel contains more chromium and manganese, the solubility of nitrogen can be significantly improved, and nitrogen alloying can be used to replace the more expensive nickel.

Boron and rare earth are trace elements in heat-resistant steel. Boron dissolves into the solid solution to distort the crystal lattice, and the boron on the grain boundary can prevent element diffusion and grain boundary migration, thereby improving the high temperature strength of steel; rare earth elements can significantly improve the oxidation resistance of steel and improve thermoplasticity.

Heat-resistant steel castings: 3Cr24Ni7N, 1cr25ni20si2, 0Cr25Ni20, 2Cr25Ni20, etc.
Heat treatment tooling: 3Cr24Ni7SiNRe, 1Cr18Ni25Si2, 1Cr25Ni20Si2, 4Cr26Ni12, etc.
High chromium wear-resistant cast iron Material: KmTBCr12, KmTBCr15Mo, KmTBCr20Mo, KmTBCr26,
Low temperature alloy steel material: 3Cr18Ni12Si2N, 0Cr18Ni9, etc.
Medium temperature alloy steel material: 3Cr24Ni7SiNRe, 1Cr18Ni9Ti, 1Cr22Ni14Si2, etc.
High temperature alloy steel material: 1Cr25Ni20Si2, 1Cr18Ni25Si2, 2Cr28Ni12NRe, 3Cr28Ni48W5, 0Cr20Ni80, etc.