[Alcoa China] Reoxidation usually occurs during the steelmaking process, especially in tundish. Severe reoxidation contaminates the cleanliness of the steel, adversely affecting the quality and performance of the steel. The purpose of this study was to focus on the negative effects of reoxidation in tundish on non-metallic inclusions in molten steel and calcium-treated aluminum killed steels compared to end products. The inclusions at various stages of RH refining, tundish, slab, and steel plate were studied on API-X70 pipeline steel. In order to obtain more accurate results, the inclusions were analyzed in a larger scanning area using an automated scanning electron microscope APEXPSEMEXPLORER. The reoxidation in the tundish was found to transform the well-formed liquid calcium aluminate into a solid Al2O3-rich inclusion, which is more likely to cause clogging of the nozzle than pure Al2O3. The amount of inclusions increases from 2.8 μm-2 after RH. It increased to 13.5 μm-2 and further decreased to 6.0 μm-2 at the slab and steel plate stage. This shows that reoxidation in the tundish renders the ability to remove inclusions strong during calcium treatment and RH treatment. The ratio of liquid inclusions is proportional to the average CaO/Al2O3 ratio in the inclusions. Large aggregates and hairline inclusions were found at 1/2 and 1/4 thickness of slabs and steel plates. The ridged inclusions in the steel plate are the products of the aggregates in the slab after rolling, which makes the steel plate unable to pass the ultrasonic inspection.
PCR instrument, also known as DNA thermal cycler and gene amplification instrument, is the basic laboratory instrument.
The PCR instrument is mainly used in many fields such as basic research and applied research, such as genetic analysis, sequence analysis, evolutionary analysis, clinical diagnosis, forensic medicine, and so on. With the continuous development of molecular biology, PCR amplification technology has also been popularized and applied.
Our company has R&D and production experience, low factory direct sales prices, complete specifications, complete qualifications, and after-sales service guarantee!
PCR machine,PCR dna thermocycler,Electric Mixer,Lab PCR Thermal Cycler,Thermal cycler,Gene cycler,PCR instrument
Changzhou Yuanwang Fluid Technology Co., Ltd. , https://www.ywfluid.com