07Cr25Ni21NbN has good resistance to water vapor and flue gas oxidation
Stainless (heat-resistant) steel
The high-temperature superheater and reheater of ultra supercritical power plant boilers are in accordance with the B5310-2008 seamless steel pipe standard for high-pressure boilers. Due to long-term operation under harsh environmental conditions, such as the inner wall number 07Cr25Ni21NbN. To withstand the oxidation of high-temperature steam above 600 ºC, the outer wall will withstand the corrosion caused by imported flue gas and fly ash erosion. Therefore, it is required that the material not only has expensive properties, but also has good thermal strength and corrosion resistance in the boiler manufacturing and power industry.
In response to the rapid development of ultra supercritical units in China, this steel type was included in 2008. Due to the low resistance to water vapor oxidation and flue gas corrosion resistance of traditional 1828 austenitic heat-resistant steel, the final components of the superheater and reheater require good resistance to water vapor and flue gas oxidation. Therefore, 25220 austenitic intercritical heat resistant steel was developed, with a Cr mass fraction of 25%. During long-term service, Cr element will diffuse towards the surface and combine with oxygen to form a dense oxide layer, playing a good antioxidant role. However, with the increase of C content, the precipitation trend of brittle o phase becomes more obvious. A high Ni content can stabilize the austenite structure while inhibiting the precipitation tendency of the o phase. Therefore, the 25220 type austenitic heat-resistant steel not only significantly improves its oxidation resistance, but also has stable austenite structure, which can adapt to the harsh working conditions of 600 ºC ultra supercritical pressure boiler with superheat tip P. The increase in cr and Ni content will not improve the creep fracture toughness. In order to improve the creep fracture strength of the material, 07Cr25Ni21NbN adopts the principle of multiple alloy strengthening, which is based on TP310. By limiting the C content and adding strong carbon nitride with a mass fraction of 0.20%~0.60%, the element Nb and N with a mass fraction of 0.15%~0.35% are formed, and the dispersed distribution of NbCrN phase, Nb rich carbon nitride, and Mz.C. To reinforce
Company Profile
Wuxi Dingyu Xinda Special Steel Co., Ltd. has world-class metallurgical equipment, mature and stable technology, and safe and reliable process flow. The smelting of special functional superalloys adopts the VIM+VAR dual vacuum dual process and the VIM+PESR+VAR triple process for smelting production; Vacuum induction melting (VIM), vacuum consumable (VAR), atmosphere protected electroslag remelting (PESR) and conventional process IF+AOD+LF+VOD metallurgical equipment. Processing equipment such as heat treatment furnaces, peeling machines, rolling straightening machines, cold drawing machines, and coreless grinders; German Spike direct reading spectrometer, hardness machine, tensile machine, impact testing machine, automatic and manual ultrasonic non-destructive testing machine, eddy current non-destructive testing machine, corrosion testing machine, salt spray testing machine, German Leica metallographic microscope and other complete testing equipment. Since 2005, Dingyu Xinda has successively passed the certifications of Lloyd's ISO quality system and PED, IATF16949, ISO13485, KR Classification Society of Korea, and AD2000 in Germany. A high-tech enterprise specializing in the research and development of high-quality special alloy functional new materials, has been committed to providing safe and reliable products for global nuclear power and high-end equipment manufacturing. The company has been focusing on special stainless steel, nickel based alloys, precision alloys, high-temperature alloys, corrosion-resistant alloys, Hastelloy alloy special steel pipes, plates, bars, profiles and forgings, pipe fittings, and flanges for 31 years. The products can also be processed according to customer drawings, and are widely used in fields such as pump valve nuclear power, aviation and military industry, automobiles and ships, medical equipment, marine engineering and petrochemical, light rail high-speed rail, compressors, turbines, etc.
Supply materials: 310S, 309S, 309Si2, 310SSi2, 254SMo, 253Ma, 904L, 304Lmod, 724L, 725LN, 316MoD, 310MoD, 310MoLN, S31050, TP316Ti, 630, 631, 17-4PH, UNS S32101, UNS S32304, UNS S31500, UNS S31803, UNS S32205, UNS S32750, UNS S32707, UNS31260, UNS 32760, UNS 39274, 304/L, 316/L, 32270 1. 347, 304H/321H/347H/347HFG/316H/316Ti/304LN/316LN/317/L/310S/310HCBN S30815/314/904L, AL-6XN No8367, N04400, N06600, N08800, GH3030, H3039, N08825, N06625, N10276, 2507, Incoloy 800, 800H, Incoloy 825, S31254, F55, S32160, 2520Si2 (S314), 0Cr25Ni22Mo2N, 901, Income926/1.4529, Incoloy 800HT, Incoloy 8020, Incoloy 825, Inconel 601, Inconel 600, Inconel 625, GH3030, GH3039, GH2080, GH140, G3, G30 series, HaC-22, HaC-276, HaC-4, HaB-2, HaB-3, etc.
All products of our company comply with national standards (GB), American standards (ASME, ASTM), Japanese standards (JIS), EN (European standard), GOST (Russian standard), our company holds the ISO9001-2008 quality system certificate issued by TUV Rheinland in Germany and the PED/97/23/EC certificate for pressure equipment in the European Union, holds the API 6A and API 17D certificates issued by the American Petroleum Association API, and is also certified by the Eight Nation Classification Society.
F A Q
1. How can I know whether you are a reliable company?
We have been engaged in the steel industry for nearly 7 years and have a high reputation in China, We welcome you to inspect our company at any time.
2. Can you guarantee your products?
Yes, we guarantee your 100% satisfaction on all our products. Please feel free to feedback us immediately.
3. Do you provide samples?
Yes, we can provide most of the product samples. We will charge a little sample fee. But we will return the charge if you place an order. if you asked to use DHL, Blue Dart Express, FedEx, etc. to send samples, you can inform us in advance to prepare.
4. Can I visit your company?
Of course, If you want to order our products and visit our company, please contact us to make an appointment.
5. Can you make boxes according to my request ?
Yes,customization service is available,OEM business is appreciated.
When you place the orders,we arrange the production asap,When finish the orders, we will inform you and also we arrange the shipping in the same time.
6. How much is the freight?
It depends on the number and transport methods. When asked about the freight, we want you to let us know your detailed information , such as the product name and quantity and your favorite mode of transport, as well as your designated port or airport. We thank you for providing us the information to estimate the cost.
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