CN110079738B

CN110079738B - High-strength American-standard rare earth sucker rod round steel and preparation method thereof

Info

Publication number: CN110079738B
Application number: CN201910454552.2A
Authority: CN
Inventors: 吕刚; 涛雅; 赵晓敏; 白月琴
Original assignee: Baotou Iron and Steel Group Co Ltd
Current assignee: Baotou Iron and Steel Group Co Ltd
Priority date: 2019-05-29
Filing date: 2019-05-29
Publication date: 2021-03-02
Anticipated expiration: 2039-05-29
Also published as: CN110079738A

Abstract

The invention discloses a high-strength American-standard rare earth sucker rod round steel which comprises the following chemical components in percentage by mass: 0.23-0.27% of C, 0.20-0.30% of Si, 0.75-0.85% of Mn, 0.50-0.60% of Cr, 0.02-0.06% of Mo, 0.77-0.87% of Ni, 0.0010-0.0030% of RE, and the balance of Fe and inevitable impurities. Its preparing process is also disclosed. The high-strength American-standard rare earth sucker rod round steel has good impact toughness, fatigue resistance and corrosion resistance, and solves the problem that the conventional sucker rod is poor in capability of bearing asymmetric cyclic alternating load in a corrosive environment.

Description

High-strength American-standard rare earth sucker rod round steel and preparation method thereof

Technical Field

The invention relates to the technical field of metallurgy, in particular to high-strength American-standard rare earth sucker rod round steel and a preparation method thereof.

Background

The sucker rod performs uninterrupted reciprocating work under the alternating action of tension-compression stress in the mechanical oil extraction process, bears the action of asymmetric cyclic alternating load in corrosive environments with different degrees for a long time, and the current sucker rod has weaker capability of bearing the action of asymmetric cyclic alternating load in the corrosive environments.

Disclosure of Invention

The invention aims to provide high-strength American-standard rare earth sucker rod round steel and a preparation method thereof.

In order to solve the technical problems, the invention adopts the following technical scheme:

the utility model provides a beautiful mark rare earth sucker rod round steel of high strength, includes the following chemical composition of mass percent: 0.23-0.27% of C, 0.20-0.30% of Si, 0.75-0.85% of Mn, 0.50-0.60% of Cr, 0.02-0.06% of Mo0.77-0.87% of Ni0.0010-0.0030% of RE, and the balance of Fe and inevitable impurities.

Furthermore, P in the impurities is less than or equal to 0.025 percent, and S in the impurities is less than or equal to 0.025 percent.

Further, the paint comprises the following chemical components in percentage by mass: 0.23-0.27% of C, 0.20-0.30% of Si, 0.75-0.85% of Mn, 0.50-0.60% of Cr, 0.02-0.06% of Mo0.77-0.87% of Ni0.0010-0.0030% of RE.

Further, the paint comprises the following chemical components in percentage by mass: 0.25 percent of C, 0.26 percent of Si, 0.81 percent of Mn, 0.56 percent of Cr, 0.03 percent of Mo, 0.78 percent of Ni, 0.013 percent of P, 0.008 percent of S and 0.0024 percent of RE.

Further, the paint comprises the following chemical components in percentage by mass: 0.26% of C, 0.24% of Si, 0.79% of Mn, 0.54% of Cr, 0.04% of Mo, 0.80% of Ni, 0.012% of P, 0.010% of S and 0.0018% of RE.

A preparation method of high-strength American-standard rare earth sucker rod round steel comprises the following steps:

smelting, wherein the C content in the molten steel at the end point of the converter is not less than 0.06 wt%, and the P content is not more than 0.03 wt%; the tapping temperature is 1620-1644 ℃;

refining;

continuous casting, wherein the superheat degree is set to be 25-35 ℃, and the drawing speed is 1.9-2.0 m/min;

and rolling, wherein the initial rolling temperature is 1000-1100 ℃, and the finish rolling inlet temperature is 900-950 ℃.

Further, in the smelting process, one or more of ferrosilicon, silicomanganese, anthracite and ferrochrome and ferronickel are added for deoxidation alloying; and carrying out bottom argon blowing operation on the ladle in the tapping process.

Furthermore, in the refining process, one or more of ferrosilicon, medium carbon ferromanganese, ferromolybdenum and calcined anthracite are added for fine adjustment of components.

Further, feeding a calcium silicate wire and a rare earth lanthanum alloy in the later stage of refining; the soft blowing time is more than 10 min. .

Compared with the prior art, the invention has the beneficial technical effects that:

the invention adjusts the contents of C, Si, Mn, Cr, Mo and Ni to the middle limit, in addition, the rare earth lanthanum alloy is added into the steel, and the rare earth lanthanum alloy has stronger affinity action with oxygen and sulfur in the steel, thereby being capable of deoxidizing, desulfurizing, reducing the oxygen content and sulfur content in the steel, and reducing the harm of low melting point elements such as phosphorus, hydrogen, arsenic, antimony, lead, tin and the like on the grain boundary. The rare earth can control the form of sulfide inclusion, the sulfide in steel is strip-shaped distributed along the rolling direction of steel material, and the addition of rare earth can make the strip-shaped sulfide become spherical or hammer-like, and can change the size of inclusion, and can obviously improve impact toughness and fatigue property. In addition, the rare earth in the steel can obviously improve the corrosion resistance of the steel and prolong the service life of the sucker rod.

Detailed Description

The 2-furnace steel is produced in an industrial trial mode, and the specific technological parameters are controlled as follows:

1. smelting in a converter

2000-3000 kg of lime, 1000-2000 kg of dolomite and 1000-3000 kg of iron sheet balls are added according to component requirements during smelting in a converter, and 130kg of ferrosilicon, 600kg of silicomanganese, 900kg of high-carbon ferrochromium and 1000kg of nickel plates are added in the tapping process.

The carbon content, phosphorus content (mass percent) and tapping temperature of the molten steel at the end of the converter are shown in Table 1.

TABLE 1 composition and temperature of converter tapping

	Tapping temperature, DEG C	Carbon content of steel tapping, wt%	Phosphorus content of tapping, wt%
				Example 1	1620	0.07	0.011
Example 2	1644	0.15	0.030

2. Refining in LF furnace

Adding auxiliary materials for slagging according to the components and temperature change of the molten steel, and adding alloy for fine adjustment and heating operation. Adding 500-600 kg of lime and 200-300 kg of bauxite, finely adjusting the alloy according to the refined in-place components, adding 50-80 kg of ferromanganese, 100-300 kg of ferrosilicon, 320kg of ferromolybdenum and 30kg of rare earth lanthanum ferroalloy, and feeding a calcium-silicon wire after refining with the feeding amount of 200-300 m.

3. Continuous casting production

The process parameters are listed in Table 2; the product ingredients are listed in table 3.

TABLE 2 continuous casting Process parameters

	Degree of superheat (. degree. C.)	Pulling speed (m/min)
			Example 1	27	1.9
Example 2	34	1.9

TABLE 3 Final product composition (wt%, balance iron)

4. Production of steel rolling

The initial rolling temperature is 1061 ℃, 1065 ℃, and the finish rolling inlet temperature is 923 ℃, 925 ℃.

The high-strength rare earth sucker rod round steel prepared in the 2 embodiments is subjected to heat treatment by taking water as a medium after quenching at 860 ℃ and tempering at 540 ℃, and then is subjected to mechanical property tests, and the test results are listed in table 5.

TABLE 5 mechanical Properties test

As can be seen from Table 5, the sucker rod round steel produced by the invention meets the standard requirements in all indexes and can meet the use requirements of users.

And simultaneously, taking a sample and carrying out real object axial fatigue inspection on a PLG-200 high-frequency fatigue testing machine. Under the condition of test stress 406Mpa, the fatigue cycle of the material object is not broken for 500 ten thousand times, which is more than the requirement that the fatigue cycle is more than 100 ten thousand times in the SY/T5029-2006 sucker rod standard.

In the description herein, the description of the terms "one embodiment," "some embodiments," "specific embodiments," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above-described embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solutions of the present invention can be made by those skilled in the art without departing from the spirit of the present invention, and the technical solutions of the present invention are within the scope of the present invention defined by the claims.

Claims

1. The utility model provides a beautiful mark rare earth sucker rod round steel of excelling in, its characterized in that includes following mass percent's chemical composition: 0.25% of C, 0.26% of Si, 0.81% of Mn, 0.56% of Cr, 0.03% of Mo, 0.78% of Ni, 0.013% of P, 0.008% of S and 0.0024% of RE;

the preparation method comprises the following steps:

refining;

2. The high-strength American-standard rare earth sucker rod round steel as claimed in claim 1, wherein in the smelting process, one or more of ferrosilicon, silicomanganese, anthracite, ferrochrome and ferronickel are added for deoxidation alloying; and carrying out bottom argon blowing operation on the ladle in the tapping process.

3. The high strength U.S. rare earth sucker rod round steel of claim 1, wherein one or more of ferrosilicon, medium carbon ferromanganese, ferromolybdenum, and calcined anthracite are added for fine adjustment of components during the refining process.

4. The high-strength American standard rare earth sucker rod round steel as claimed in claim 3, wherein the silicon-calcium wire and the rare earth lanthanum alloy are fed in the later stage of refining; the soft blowing time is more than 10 min.