ZG35Cr24Ni7SiN pipe is a high-chromium-nickel austenitic stainless steel, which has excellent corrosion resistance.
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.
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 also developed. Heat-resistant steel and stainless 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.
ZG35Cr24Ni7SiN adopts vacuum solid mold casting, centrifugal casting, resin sand casting, silica sol casting, water glass sand casting and other production processes, and has medium frequency induction furnace, electric arc furnace, refining furnace and other smelting equipment. Greater impact. When the solution temperature is lower than 1050 ℃, the grain growth rate is not obvious; when the temperature is higher than 1050 ℃, the grain size grows rapidly with the increase of the solution treatment temperature. When the Inconel600 alloy is solution treated below 1050℃, the hardness value remains basically unchanged, and reaches the maximum value at 1050℃, and decreases with the increase of solution treatment temperature above 1050℃. Inconel600 alloy has excellent resistance to sulfuric acid-iron sulfate intergranular corrosion after solution treatment. After solid solution at 1100 °C, carbides can be fully dissolved. Considering the effect of solid solution degree and grain size on properties, it is recommended that the solution treatment temperature of Inconel600 alloy be 1050-1100 °C.
| Element | Min | Max |
| N (%) | 0.2 | 0.28 |
| S (%) | - | 0.03 |
| P (%) | - | 0.04 |
| Ni (%) | 7 | 8.5 |
| Cr (%) | 23 | 25.5 |
| Mn (%) | 0.8 | 1.5 |
| Si (%) | 1.3 | 2 |
| C (%) | 0.3 | 0.4 |
Nickel (Ni): Nickel increases the strength of steel while maintaining good ductility and toughness. Nickel has high corrosion resistance to acid and alkali, rust and heat resistance at high temperature. However, since nickel is a relatively scarce resource (high price), other alloying elements should be used instead of nickel-chromium steel.
Chromium (Cr): In alloy steels, chromium can significantly improve strength, hardness and wear resistance, while reducing plastic toughness. Chromium can also improve the oxygen and corrosion resistance of steel, so stainless steel is an important alloying element of heat-resistant steel.
Molybdenum (Mo): Molybdenum can refine the grains of steel, improve hardenability and thermal strength, and maintain sufficient strength and creep resistance at high temperatures (long-term stress at high temperatures, deformation occurs, called creep ). The addition of molybdenum to alloy steel can improve mechanical properties. Alloy steels can also be brittle due to fire. It can improve redness in tool steel.
Cobalt (Co): Cobalt is a rare precious metal used in special steels and alloys, heat-resistant strong steels and magnetic materials.
| Properties | Data |
| Yield Rp0.2 (MPa) | 929 (≥) |
| Tensile Rm (MPa) | 529 (≥) |
| Impact KV/Ku (J) | 44 |
| Elongation A (%) | 23 |
| Reduction in cross section on fracture Z (%) | 24 |
| As-Heat-Treated Condition | Solution and Aging, Annealing, Ausaging, Q+T,etc |
| Brinell hardness (HBW) | 441 |
| Temperature (°C) | 42 | 241 | 811 |
| Modulus of elasticity (GPa) | - | 957 | - |
| Mean coefficient of thermal expansion 10-6/(°C) between 20(°C) and | - | - | 33 |
| Thermal conductivity (W/m·°C) | 24.3 | 42.2 | |
| Specific thermal capacity (J/kg·°C) | 142 | ||
| Specific electrical resistivity (Ω mm²/m) | 0.12 | ||
| Density (kg/dm³) | - | - | 142 |
| Poisson’s coefficient, ν | 142 |
ZG10Cr13NiMo is mainly suitable for castings of high-temperature nitric acid concentration equipment not subject to impact load, such as pumps, valves, etc.; it can also be used to manufacture sodium hypochlorite and phosphoric acid equipment and high-temperature oxidation-resistant heat-resistant components.
ZG35Cr24Ni7SiN liner can be used continuously at 1000-1300 ℃ in high temperature environment, and has good thermal fatigue resistance and performance. It is not easy to produce hot cracking phenomenon after repeated use. The operating temperature can reach above 1400 ℃, and the product quality is stable. The formation of the zone inhibits the occurrence of sliding wear and promotes the gradual reduction of the friction coefficient and wear amount. The tribo-oxidation mainly occurs in the micro-slip zone of the wear scar, and the central adhesion zone is relatively rare; the distribution of oxygen elements is more concentrated at high temperature than at room temperature. The surface oxygen content of the central adhesion zone is low, and a large amount of Ni, Cr and Fe elements exist in the surface layer; the surface oxides of the wear scar are composed of NiO, Cr2O3 and Fe3O4. At room temperature and high temperature, micro-cracks occurred at the interface between the adhesion zone and the micro-slip zone on the surface of the wear scar. At high temperature, the cracks were initiated in the micro-slip zone. Compared with room temperature, the number of cracks initiated at high temperature was smaller and the length was smaller.
| Type | Products | Dimension | Processes | Deliver status |
| Plates/ Sheets | Plates/ Sheets | 0.08-200mm(T)*W*L | Forging, hot rolling and cold rolling | Annealed, Solution and Aging, Q+T, ACIDWASHED, Shot Blasting |
| Steel Bar | Round Bar, Flat Bar, Square Bar |
Φ8-1200mm*L | Forging, hot rolling and cold rolling, Cast | Black, Rough Turning, Shot Blasting |
| Coil / Strip | Steel Coil /Steel Strip | 0.03-16.0x1200mm | Cold-Rolled and Hot- Rolled | Annealed, Solution and Aging, Q+T, ACIDWASHED, Shot Blasting |
| Pipes / Tubes | Seamless Pipes/Tubes, Welded Pipes/Tubes |
OD:6-219mm x WT:0.5-20.0mm |
Hot extrusion, Cold drawn, Welded | Annealed, Solution and Aging, Q+T, ACIDWASHED |
Ceramic lined pipe is made through self-propagating high-temperature synthesis (SHS) technique.
Cast basalt lined steel pipe is composed by lined with cast basalt pipe, outside steel pipe and cement mortar filling between the two layers.
Ceramic tile lined pipes have very uniform coating of specially formulated ceramic material that is affixed to the inner of the pipe.
The material of the rare earth alloy wear-resistant pipe is ZG40CrMnMoNiSiRe, which is also the grade of rare earth alloy steel.
Tubes Erosion Shields are used to protect boiler tubing from the highly erosive effects of high temperatures and pressures thereby greatly extending tube life.
The ASTM A213 T91 seamless tubes are primarily used for boiler, superheater, and heat-exchanger.
