The Grade, Chemical Composition, Structure, Performance And Application Of 254SMo Steel
获取链接
Facebook
X
Pinterest
电子邮件
其他应用
254SMo steel (S31254, 00Cr20Ni18M06CuN) is one of the earliest super austenitic stainless steels developed in the 1970s. It not only has good overall corrosion resistance in reducing media, but also has excellent resistance in chloride-containing media The performance of local corrosion such as pitting corrosion and crevice corrosion. At the same time, the strength of this steel is higher than that of general chromium nickel austenitic stainless steel due to the strengthening effect of nitrogen. It is precisely because of these characteristics that 254SMo steel has become increasingly widely used, and it can also replace high nickel corrosion-resistant alloys in some applications.
Chemical composition and organizational characteristics of 254SMo
The solid solution state of 254SMo is a single austenite structure, but it is affected by the thermal history. For example, carbides and intermetallic phase compounds will precipitate in the heat affected zone during the cooling process of hot working and after welding, due to the carbon content in the steel It is very low, so it is mainly the X phase, α phase, β and other intermetallic phases and the precipitation of Cr2N is the TTP (temperature-time-precipitation) curve of 254SMo containing 0.21% N. The kinetic curves of the intermetallic phase precipitation of 254SMo steel and the comparison results with the phases containing molybdenum (316) and high molybdenum (904L and 317LMN). It can be seen that the most sensitive temperature for the precipitation of inter-general phases in this steel is 800~900°C. Because 254SMo steel has high chromium and molybdenum content and low nitrogen content, the sensitivity of intermetallic phase precipitation is higher than that of high-molybdenum austenitic stainless steel 904L (0OCr20Ni25Mo4.5Cu), 317LMN and low-molybdenum 316. For this reason, appropriate measures should be taken to prevent the precipitation of intermetallic phases during 254SMo hot forming and welding.
Mechanical properties
TTP curve of steel 254SMo containing 0.21% of N
Kinetic curve of intermetallic phase precipitation between 254SMo steel and 316,904L and 317LMN
Duplex Stainless Steel Pipe for Nuclear Power Cooling Water System As a clean energy, nuclear power is a major contributor to global carbon emissions reduction, and it can play a greater role in the future. Duplex stainless steel pipe for cooling water system is the future. The key factor for the safe operation of nuclear power plants is the cooling water piping system. This complex system contains thousands of feet of pipes with diameters ranging from large to small, and its function is to provide reliable water supply for the cooling of nuclear power plant equipment. There is usually a non-safety-level operating system and a safety-level emergency system. Non-safety-grade piping systems must provide sufficient cooling water for normal cooling of nuclear power equipment. The safety-level system must provide sufficient cooling water to keep the reactor under control and shut down safely in an emergency. The piping materials used in these systems must be resistant to corrosio...
Brief introduction of crevice corrosion test project Crevice corrosion is the phenomenon that metal surfaces form gaps due to the presence of foreign objects or structural reasons, resulting in accelerated metal corrosion in the gaps. The width of the slit or gap that causes crevice corrosion must be sufficient to allow the medium to enter and stay in it. When the crevice width is between 25 and 100 μm, it is the most sensitive range for crevice corrosion. In some wider crevices, the corrosive medium is easy flowing, crevice corrosion generally does not occur. The result of crevice corrosion will lead to a reduction in the strength of the component and a poor fit. The increase in the volume of corrosion products in the crevices will cause local additional stress, which not only makes assembly difficult, but may also reduce the bearing capacity of the component. Crevice corrosion of metals shows the following main features: (1) Whether it is the contact of the same or different...
Affected By The Covid-19 Epidemic, The Situation Of Stainless Steel Flanges Is Not Optimistic 1. Global financial market turmoil, stainless steel flange futures plunged After the Chinese New Year, in the category of commodities related to economic growth, the strongest asset is the stainless steel flange. WN Flange As the overseas epidemic became more serious, Chinese finished product exports were affected. The domestic production of stainless steel flanges continues to pick up sharply, and the pressure of destocking is still relatively large. The oversupply of finished materials is a foregone conclusion. On the 27th, the Politburo meeting pointed out that it is necessary to speed up the issuance and use of local government special bonds, increase the fiscal deficit rate, and guide the loan market interest rate to fall, which will be beneficial to the restoration of confidence in the stainless steel flange market. However, Monday's futures still weakened signif...
评论
发表评论