What are the key technologies that need to be solved for special steel continuous casting based on the solidification characteristics of special steel

 　　(1) Improving the cleanliness of molten steel

　　The main measures to improve the cleanliness of molten steel include: 1) Low aluminum clean steel technology, which uses non aluminum deoxidizers to significantly reduce the oxygen content in steel compared to traditional aluminum deoxidization, while reducing the proportion of residual aluminum and oxide inclusions in A1203; 2) Soft argon blowing technology for ladle; 3) Automatic detection and control technology for ladle slag discharge; 4) Tundish metallurgical technology; 5) Optimization of tundish and crystallizer protective slag; 6) Crystallizer Metallurgical Technology.

　　(2) Improving the quality of casting billets

　　The improvement of slab quality mainly depends on the optimization of continuous casting equipment and process. As far as the existing equipment in China is concerned, the main measure to improve the quality of special steel slab is to adopt the method of combining low superheat casting with electromagnetic stirring to expand equiaxed crystal zone and reduce segregation and loose concentration ratio. At the same time, appropriate protective slag, mold design and cooling, secondary cooling, and drawing systems are selected based on the characteristics of different steel grades to prevent the occurrence of defects such as cracks.

　　In order to further improve the quality of the casting billet, some new technologies have emerged in recent years: 1) automatic control of the liquid level during the casting process; 2) Optimization of electromagnetic stirring process for crystallizer and solidification end stage; 3) Soft reduction technology for bloom; 4) Using external fields or nucleating agents to refine the as cast microstructure technology; 5) Composite crystallizer control solidification structure technology; 6) Mold steel flow control technology, etc.



评论

发表评论

此博客中的热门博文

Japanese Standard (1)

图片
 　　In the grades of Japanese steel (JIS series), ordinary structural steel mainly consists of three parts to represent the material. 　　For example, S (Steel) represents steel, F (Ferrim) represents iron; The second part represents different shapes, types, and uses, such as P (Plate) for plates, T (Tube) for tubes, and K (Kogu) for tools; The third part represents the characteristic number, which is generally the tensile strength. For example, SS400 represents Steel, the second S represents Structure, 400 represents the lower limit tensile strength of 400MPa, and the overall represents ordinary structural steel with a tensile strength of 400MPa.
阅读全文

National Standard Properties of 304 Stainless Steel Plate

图片
　　 304 stainless steel plate tensile strength (Mpa) 520 　　Yield strength of 304 stainless steel plate (Mpa) 205-210 　　Elongation rate of 304 stainless steel plate (%) 40% 　　304 stainless steel plate hardness HB187 HRB90 HV200 　　The density of 304 stainless steel is 7.93 g/cm3. Austenitic stainless steel generally uses this value. The chromium content (%) of 304 is 17.00 to 19.00, and the nickel content (%) is 8.00 to 10.00304, which is equivalent to 0Cr19Ni9 (0Cr18Ni9) stainless steel in China 　　304 stainless steel is a versatile stainless steel material with stronger rust resistance than the 200 series stainless steel material. It also has good resistance to high temperatures. 　　304 stainless steel has excellent rust resistance and good intergranular corrosion resistance. 　　For oxidizing acids, it was found in experiments that 304 stainless steel has strong corrosion resistance in nitric acid below boiling temperature with a concentration of ≤ 65%. It also has good cor...
阅读全文

Similarities and Differences in Performance between N08367 and N08926

图片
 　　Today, let's talk about the similarities between the two. UNS N08367 and 1.4529 (N08926) materials are both super austenitic stainless steel. High Cr, high Mo, high corrosion resistance, and excellent corrosion resistance in harsh environments such as high-temperature seawater or smoke exhaust desulfurization devices. Under certain conditions, it has corrosion resistance comparable to Hastelloy and pure titanium, making it a cost-effective stainless steel. 　　If the performance is similar, the components must be very similar. 　　I'll show you the ingredient list and you'll know. 　　Except for the Cu element, which has a smaller intersection (0.5-0.75%), all other elements have a larger space, which means that other components can be completely identical. 　　So the two are basically the same and can to some extent replace each other. 　　The commonly used pitting resistance index (PRE) for stainless steel expresses the degree of corrosion resistance. 　　The calcul...
阅读全文