Effect of microstructure and hardness of duplex stainless steel

　　Duplex stainless steel refers to stainless steel in which the ferrite phase and the austenite phase each account for about half (volume fraction) after solution treatment. In general, the content of less phase is at least 30%. This type of steel combines the characteristics of austenitic and ferritic stainless steels with outstanding mechanical and corrosion resistance properties, and is primarily used in petroleum, chemical, construction, and marine industries. Carbon is one of the most useful and economical elements of advanced alloy strength, but so far there has been less discussion about the arrangement and function of high carbon duplex stainless steel.

　　The researchers applied high temperature carbon duplex stainless steel 20Cr25Ni11Mo3CuWV to solution treatment and aging treatment at different temperatures. Optical microscope (OM), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and X-ray diffractometry (XRD) were used. The arrangement was changed and analyzed. The hardness test was used to explore the effect of different solid solution and aging temperature on the hardness of the alloy. the result shows:

　　(1) After high-carbon duplex stainless steel 20Cr25Ni11Mo3CuWV is solution treated, the residual particles are arranged as chromium carbide in the arrangement. When the solution temperature reaches 1250 °C, it can not be completely dissolved.

　　(2) During the solution treatment, the alloy's ferrite phase content is continuously increased with the increase of solid solution temperature. The hardness of the alloy is 25.8HRC when it is solution treated at 1150 °C.

　　(3) After the solution treatment at 1150 °C, the alloy is aged at different temperatures and exhibits two hardness peaks. The difference is 450 °C (38.1HRC) and 700 °C (52.9HRC). The former is because of ferrite. The intra-phase amplitude modulation differentiation precipitated a chromium-rich phase and an iron-rich phase with coherent linkages. The latter was mainly due to the fact that many σ phases were uniformly deposited in the ferrite phase due to the change of eutectoid.

评论

发表评论

此博客中的热门博文

The difference between high-quality seamless steel tubes and inferior seamless steel tubes

　　In daily steel procurement, the most irritating and irritating thing is the purchase of inferior seamless steel tubes, which affects product quality. How to identify inferior seamless steel pipe? Here we identify through the following methods: 　　1, poor quality seamless steel pipe surface is prone to scarring. 　　Mainly due to two reasons: 　　(1) There are many impurities in the inferior seamless steel tubes and the materials are not uniform. 　　(2) Inadequate guide equipment for poor quality pipe manufacturers is particularly prone to sticking steel. Contaminated pipes tend to produce scars when they bite into the roll. 　　2, poor quality seamless steel pipe is prone to tube folding. 　　The so-called folding is a variety of fold lines formed on the surface of the seamless steel pipe, and this defect often runs through the entire product. The reason for the folding is that the manufacturer is pursuing high efficiency in order to increase the output. In the production process, ...
阅读全文

Repeated order from regular Singapore Customer–ERW Steel pipe

Project location：Indonesia Product：ERW steel pipe Standard and material：ASTM A53 GRB;EN10219 S355J2H Specifications：88.9*5.49*6000mm;273.1*12.5*11800mm;355.6*12.5*6000mm;406.4*12.5*6000mm Application：stock use Arrival time：2024.1.10 This order is for a customer in Singapore. After receiving goods of the first order, the customer gave great recognition to Xinyue’s comprehensive services and product quality. We signed a second contract soon. The delivery date required by the customer for this order was very urgent. Xinyue formulated a plan and mobilized rescources immediately. We finally delivered the product on time while ensuring that the product met specifications and quality requirements. Xinyue is committed to establishing long-term partnerships with customers. We provide customers with personalized solutions and professional technical support to meet the needs of different projects and markets. We adhere to customer satisfaction as the center and continuously improv...
阅读全文

GCr15 tube heat treatment process parameters

　　GCr15 Pipe is a high carbon chromium bearing steel with less alloy content, good performance and wide application. After quenching and tempering, it has high and uniform hardness, good wear resistance and high contact fatigue performance. The cold working of the steel is medium in plasticity, the cutting performance is general, the welding performance is poor, the sensitivity to white spots is large, and the temper brittleness is obtained. 　　Chemical composition / element content (%) 　　C: 0.95-1.05 Mn: 0.20-0.40 Si: 0.15-0.35 S: <=0.020 P: <=0.027 Cr: 1.30-1.65 　　The heat treatment system is: steel bar annealing, annealing or oil quenching at 830-840 °C. 　　Heat treatment process parameters: 　　1. Ordinary annealing: heating at 790-810 °C, after the furnace is cooled to 650 °C, air cooling - HB170-207 　　2. Isothermal annealing: 790-810 ° C heating, 710-720 ° C isothermal, air cooling - HB207-229 　　3. Normal fire: 900-920 ° C heating, air cooling - HB270-390 　　4. H...
阅读全文