Low-alkalinity synthetic slag for external refining of boiler tube steel

A technology of synthetic slag and low basicity, applied in the field of steelmaking, can solve the problems of poor oxidation resistance, not strictly controlling the FeO+MnO content of the refining synthetic slag, and poor inclusion capacity.

A technology of synthetic slag and low basicity, applied in the field of steelmaking, can solve the problems of poor oxidation resistance, not strictly controlling the FeO+MnO content of the refining synthetic slag, and poor inclusion capacity.

CN102912082AInactive Publication Date: 2013-02-06UNIV OF SCI & TECH BEIJING
5 Cites 7 Cited by

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Low-alkalinity synthetic slag for external refining of boiler tube steel
  • Low-alkalinity synthetic slag for external refining of boiler tube steel

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0018] According to the chemical composition range described in the present invention, 4 batches of high alkalinity synthetic slags were prepared. Using synthetic slag in a 10kg vacuum induction furnace, four heats of molten steel were refined. According to the batch number of the synthetic slag, it is added to the molten steel of the corresponding furnace number. After the synthetic slag is added, blow argon and stir the molten steel for 15 minutes, then add silicon-calcium wire for calcium treatment, blow argon and stir weakly for 8 minutes before pouring the ingot. Steel samples were taken from the molten steel before the refining slag was added and from the final ingot. The total oxygen content of the steel samples was analyzed, and the morphology and composition of inclusions in steel were analyzed by scanning electron microscope (SEM) + energy dispersive spectroscopy (EDS); the morphology and quantity of inclusions in steel were analyzed by optical microscope. The resu...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
sizeaaaaaaaaaa
Login to View More

Abstract

The invention relates to a low-alkalinity synthetic slag for external refining of boiler tube steel, wherein CaO, Al2O3, MgO, SiO2 and CaF2 are used as basic components in the synthetic slag; the alkalinity range of the synthetic slag is controlled; and the synthetic slag comprises the following specific chemical compositions in percentage by weight: 48-55% of CaO, 18-25% of Al2O3, 6-8% of MgO, 14-18% of SiO2, 25% of CaF and smaller than 1% of MnO and FeO, wherein the alkalinity of the synthetic slag is 3-3.5. Compared with the traditional synthetic slag for external refining of boiler tube steel, the oxidbillity of refining slag is strictly controlled so that the content of MnO and FeO is smaller than 1%; the oxygen activity of liquid steel balanced with the synthetic slag is promoted to be decreased; and the total oxygen in the steel can be controlled between 12ppm and 15ppm. The alkalinity of the synthetic slag is kept between 3 and 3.5; and the refining slag keeps good melting, flowing, adsorption and desorption abilities of slag inclusion while having good deoxidating and desulphurizing abilities.

Description

technical field [0001] The invention belongs to the technical field of steelmaking, and specifically relates to a synthetic slag for refining outside a furnace, which is especially suitable for deoxidation and controlled removal of inclusions in molten steel for high-pressure boiler tube steel. Background technique [0002] With the continuous development of science and technology, the requirements for steel quality are becoming more and more stringent, forcing the steelmaking process and technology to be updated and developed continuously to produce clean steel and ultra-clean steel to improve the quality and performance of steel. For this reason, the accelerated progress of refining desulfurization, deoxidation, and inclusion control technology is required to meet the quality level of products. For the steel used for boiler tubes, because the high-pressure boiler tubes often work under high pressure and high temperature for a long time, the service conditions are relativel...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
06 Feb 2013
Publication
CN102912082A
IPC
C21C7/06; C21C7/076
CPC
Y02P10/20
Inventors
孙彦辉; 方忠强