阅读说明：本技术 一种高速轨道钢的冶炼工艺 (A kind of smelting process of high-speed track steel ) 是由 张玉亭 刘宪民 马斌 窦晓光 于 2019-08-20 设计创作，主要内容包括：本发明公开了一种高速轨道钢的冶炼工艺,所述冶炼工艺包括转炉冶炼和精炼工序；所述转炉冶炼工序,转炉出钢加白灰、萤石、硅钡钙；所述精炼工序,精炼到位喂纯钙线、电石、碳化硅粉。本发明转炉出钢降低白灰用量,可显著提高炉渣对于夹杂物的吸附能力；加入萤石,防止炉渣结坨；提高转炉出钢温度,有助提高炉渣的流动性；精炼到位喂入钙线,可尽快脱除钢中氧,促进脱硫,促进钢中铝氧化物向复合夹杂物方向转变,喂入电石对钢水污染少,可减少炉渣中Al<Sub>2</Sub>O<Sub>3</Sub>的含量,加入石英砂提高炉渣对于钢中Al<Sub>2</Sub>O<Sub>3</Sub>夹杂物的吸附能力。本发明冶炼工艺生产的高速轨道钢中铝含量≤0.004%,显著降低,符合用户要求,极大提高了高速轨道钢的品质。(The invention discloses a kind of smelting process of high-speed track steel, the smelting process includes converter smelting and refining procedure；The converter smelting process, converter tapping add lime, fluorite, silicon barium calcium；Pure calcium line, calcium carbide, carborundum powder are fed in the refining procedure, refining in place.Converter tapping of the present invention reduces lime dosage, is remarkably improved clinker for the adsorption capacity of field trash；Fluorite is added, prevents clinker knot from sticking together；Tapping Temperature of Bof is improved, the mobility for improving clinker is helped；Refining feeds calcium line in place, can remove oxygen in steel as early as possible, and promotion desulfurization promotes aluminum oxide in steel to change to complex inclusion direction, and feeding calcium carbide pollutes less molten steel, can reduce Al in clinker 2 O 3 Content, be added quartz sand improve clinker for Al in steel 2 O 3 The adsorption capacity of field trash.Aluminium content≤0.004% in the high-speed track steel of smelting process production of the present invention, significantly reduces, and meets user's requirement, greatly improves the quality of high-speed track steel.)

1. a kind of smelting process of high-speed track steel, which is characterized in that the smelting process includes converter smelting and refining procedure； The converter smelting process, converter tapping add lime 5-6 ㎏/t steel plus fluorite 1-2 ㎏/t, silicon barium calcium 0.9-1.5 ㎏/t steel；Institute Refining procedure is stated, pure calcium line 0.05-0.09 ㎏/t steel, calcium carbide 0.4-0.6 ㎏/t steel, carborundum powder 0.5-1.5 are fed in refining in place Quartz sand 0.8-1.5 ㎏/t steel, fluorite 1-2 ㎏/t steel is added in ㎏/t steel, refining process.

2. a kind of smelting process of high-speed track steel according to claim 1, which is characterized in that the converter smelting work Sequence, Tapping Temperature of Bof are controlled at 1610-1640 DEG C.

3. a kind of smelting process of high-speed track steel according to claim 1, which is characterized in that the lime is at grouping At: CaO >=85%, SiO₂≤ 3.5%, MgO≤5%, igloss≤7%.

4. a kind of smelting process of high-speed track steel according to claim 1, which is characterized in that the fluorite is at grouping At: CaF >=75%, SiO₂≤ 23%, S≤0.2%.

5. a kind of smelting process of high-speed track steel according to claim 1, which is characterized in that the calcium carbide CaC₂: it gets angry Amount >=260L/ ㎏.

6. a kind of smelting process of high-speed track steel according to claim 1, which is characterized in that SiO in the quartz sand₂: 97.5-98.5%。

7. a kind of smelting process of high-speed track steel described in -6 any one according to claim 1, which is characterized in that the smelting The high-speed track steel of sweetening process production: Al≤0.004%.

8. a kind of smelting process of high-speed track steel described in -6 any one according to claim 1, which is characterized in that the smelting The high-speed track Steel Properties of sweetening process production: tensile strength 980-1180MPa, elongation after fracture 10-12%, hardness 290- 330HBW。

9. a kind of smelting process of high-speed track steel described in -6 any one according to claim 1, which is characterized in that the smelting The high-speed track steel non-metallic inclusion of sweetening process production: A class is carefully≤0.5 grade, A class is slightly≤0.5 grade, and B class is carefully≤0.5 Grade, B class are slightly≤0.5 grade, and C class is carefully 0 grade, C class is slightly 0 grade, and D class is carefully≤1.0 grades, D class is slightly≤0.5 grade.

Technical field

The invention belongs to metallurgical technology fields, and in particular to a kind of smelting process of high-speed track steel.

Background technique

With being continuously increased for railway transportation density, running speed and axis weight, the fatigue damage of rail and abrasion are increasingly Frequently, it is influenced caused by also increasingly severe.Studies have shown that steel can be effectively improved by limiting aluminium content in steel for seamed high-speed steel rail The fatigue life of rail.

Aluminium is oxidizable element, and pure aluminum and its oxide are widely present among our various materials, therefore by aluminium Control is great in extremely low level (high-speed track steel aluminium content≤0.004%) difficulty.

All the time, the production of rail steel, converter tapping add 400-500 kilograms of lime, 300-400 kilograms of pre-melted slag, add 90-100 kilograms of calcium of silicon barium.Refining position is diffused deoxidation using silicon carbide and aluminum shot, and aluminium content can achieve 0.0080- in steel 0.0150%.And low aluminum steel requires aluminium content to reach 0.0040% hereinafter, therefore, for low aluminum steel, although strictly control alloy and The aluminium oxide content of supplementary material, but low aluminium requirement below for 0.0040%, once stagnated, and were not able to satisfy user's requirement.

Therefore, for deoxidization technique and slagging process, carry out technical study, realize the steady production of low aluminum steel, there is weight The Social benefit and economic benefit wanted.

Summary of the invention

The technical problem to be solved in the present invention is to provide a kind of smelting processes of high-speed track steel.The invention smelting process is raw Aluminium content≤0.004% in the high-speed track steel of production significantly reduces, greatly improves the quality of high-speed track steel.

In order to solve the above technical problems, the technical solution used in the present invention is: a kind of smelting process of high-speed track steel, The smelting process includes converter smelting and refining procedure；The converter smelting process, converter tapping add lime 5-6 ㎏/t steel, Add fluorite 1-2 ㎏/t, silicon barium calcium 0.9-1.5 ㎏/t steel；Pure calcium line 0.05-0.09 ㎏/t is fed in the refining procedure, refining in place Quartz sand 0.8-1.5 ㎏/t steel, firefly is added in steel, calcium carbide 0.4-0.6 ㎏/t steel, carborundum powder 0.5-1.5 ㎏/t steel, refining process Stone 1-2 ㎏/t steel.

Converter smelting process of the present invention, Tapping Temperature of Bof are controlled at 1610-1640 DEG C.

Lime of the present invention is at being grouped as: CaO >=85%, SiO₂≤ 3.5%, MgO≤5%, igloss≤7%.

Fluorite of the present invention is at being grouped as: CaF >=75%, SiO₂≤ 23%, S≤0.2%.

Calcium carbide CaC of the present invention₂: gas forming amount >=260L/ ㎏.

SiO in quartz sand of the present invention₂: 97.5-98.5%.

The high-speed track steel of smelting process production of the present invention: Al≤0.004%.

The high-speed track Steel Properties of smelting process production of the present invention: tensile strength 980-1180MPa, elongation after fracture 10-12%, hardness 290-330HBW.

The high-speed track steel non-metallic inclusion of smelting process of the present invention production: A class is carefully≤0.5 grade, A class is slightly ≤ 0.5 grade, B class is carefully≤0.5 grade, B class is slightly≤0.5 grade, and C class is carefully 0 grade, C class is slightly 0 grade, and D class is carefully≤1.0 grades, D Class is slightly≤0.5 grade.

The chemical component composition and mass percentage of the high-speed track steel of smelting process production of the present invention are as follows: C: 0.70-0.76%, Si:0.15-0.40%, Mn:1.10-1.20%, S≤0.020%, P≤0.010%, Al≤0.004%, V≤ 0.03%, Mo≤0.02%, Ni≤0.10%, Cu≤0.15%, Ti≤0.025%, Nb≤0.01%, remaining is for Fe and inevitably Impurity

Mentality of designing of the present invention is as follows:

1. converter tapping slag former, appropriate to reduce lime dosage, it is intended that reduce basicity of slag, improve the mobility of clinker；It is added Fluorite, it is therefore an objective to clinker be diluted as early as possible, prevent clinker knot from sticking together；The raising of slag fluidity is remarkably improved clinker for folder The adsorption capacity of sundries can effectively improve slagging speed and change slag system composition, by CaO- compared with using pre-melted slag slugging Al₂O₃-SiO₂- MgO system is changed to CaO-SiO₂- CaF-MgO slag system, Al in slag system₂O₃Activity significantly reduce, clinker is in steel Al₂O₃The adsorption capacity of field trash just greatly reinforces, Holo-Al content and then rapid decrease in steel.

2. Tapping Temperature of Bof is appropriate more slightly higher, the mobility for improving clinker is helped.

3. refining feeds appropriate calcium line in place, oxygen in steel can be removed as early as possible, promote desulfurization, aluminum oxide is to again in promotion steel The transformation of co-clip sundries direction, complex inclusion agglomeration, with the process of refining, Cong Gangzhong is moved on in clinker.The master of calcium carbide Wanting ingredient is CaC₂, have very strong deoxidizing capacity, while few, Al in reduction clinker is polluted to molten steel₂O₃Content.

4. the main component of quartz sand is SiO₂, further strengthen refining CaO-SiO₂- CaF slag system improves clinker for steel Middle Al₂O₃The adsorption capacity of field trash.

A kind of high-speed track steel product canonical reference " 43-75 ㎏/m of the smelting process production of high-speed track steel of the present invention Rail order technical conditions GB/2344-2012 "；Product inspection method canonical reference " steel and iron chemical constituents determination method GB/ T20066 ", " macrostructure and defect analysis method GB/T226 of steel ", " nonmetallic inclusionsin steel assay evaluation side Method GB/T10561 ".

The beneficial effects of adopting the technical scheme are that 1, converter tapping of the present invention reduces lime dosage, it can Basicity of slag is reduced, the mobility of clinker is improved, is remarkably improved clinker for the adsorption capacity of field trash.2, converter of the present invention Fluorite is added in tapping, can dilute clinker, prevent clinker knot from sticking together.3, the present invention improves Tapping Temperature of Bof, helps and improves clinker Mobility.4, present invention refining feeds calcium line in place, can remove oxygen in steel as early as possible, promotes desulfurization, promote in steel aluminum oxide to The transformation of complex inclusion direction, complex inclusion agglomeration, with the process of refining, Cong Gangzhong is moved on in clinker.5, this hair The bright calcium carbide main component used is CaC₂, molten steel is polluted less, has very strong deoxidizing capacity, Al in clinker can be reduced₂O₃Contain Amount.6, the quartz sand main component that the present invention uses is SiO₂, further strengthen refining CaO-SiO₂- CaF slag system improves clinker For Al in steel₂O₃The adsorption capacity of field trash.7, aluminium content in the high-speed track steel of smelting process of the present invention production≤ 0.004%, it significantly reduces, greatly improves the quality of high-speed track steel.8, the high-speed track rigidity of smelting process production of the present invention Can: tensile strength 980-1180MPa, elongation after fracture 10-12%, hardness 290-3300HBW；High-speed track steel nonmetal inclusion Object: A class is carefully≤0.5 grade, A class is slightly≤0.5 grade, and B class is carefully≤0.5 grade, B class is slightly≤0.5 grade, and C class is carefully 0 grade, C class It is slightly 0 grade, D class is carefully≤1.0 grades, D class is slightly≤0.5 grade, and the content of aluminium oxide non-metallic inclusion is greatly lowered in steel.

Specific embodiment

Present invention will be explained in further detail combined with specific embodiments below.