CN116287980A - Wire rod for annealing-free corrosion-resistant mechanical part and preparation method thereof - Google Patents

Abstract

The invention discloses an annealing-free corrosion-resistant wire rod for mechanical parts, which comprises the following chemical components in percentage by mass: 0.35 to 0.42 percent of C, 0.20 to 0.45 percent of Si, 030 to 0.60 percent of Mn, 1.35 to 1.65 percent of Cr, 0.07 to 1.10 percent of Al, 0.15 to 0.25 percent of Mo, less than or equal to 0.020 percent of S, less than or equal to 0.020 percent of P, less than or equal to 0.0020 percent of O, less than or equal to 0.0040 percent of N, and the balance of Fe and unavoidable impurities. Its preparing process is also disclosed. The invention aims to provide a wire rod for a spheroidizing annealing-free corrosion-resistant fastener and a preparation method thereof, which can improve the atmospheric corrosion resistance of a material on the basis of a conventional fastener, can avoid the spheroidizing annealing step, is directly used for drawing and cold heading, and overcomes the defects of the conventional product.

Description

Wire rod for annealing-free corrosion-resistant mechanical part and preparation method thereof

Technical Field

The invention relates to the technical field of ferrous metallurgy, in particular to an annealing-free corrosion-resistant wire rod for mechanical parts and a preparation method thereof.

Background

Alloy structural steel, which performs the national standard GB/T3077-2015. After quenching and tempering, the hardness value of the workpiece is not lower than 45. The workpiece has higher strength and toughness, high surface hardness and good wear resistance, and is commonly used for manufacturing mechanical parts which work under the conditions of impact load and reciprocating wear, such as boring cutter bars, grinding machine spindles, automatic lathe spindles and various wear-resistant parts on rubber extruders.

At present, with the continuous development of engineering equipment, the requirements on the number and the quality of high-performance mechanical parts are also continuously increased, and especially the mechanical parts working in a severe environment are also continuously increased. The common mechanical parts are usually carbon structural steel, and usually only contain basic chemical elements such as C, si, mn and the like, such as SWRCH35K and the like, while some low alloy steels such as SCM435 and the like are also subjected to corrosion prevention treatment by adding certain sums to improve the strength of the mechanical parts and adopting a surface coating and other methods. The manufactured mechanical parts are not sufficient to be in service for a long time in a corrosive environment. In addition, these mechanical parts often need to be spheroidized during production and manufacturing, which tends to cause environmental pollution and increase in cost. Therefore, there is an increasing demand for spheroidizing annealing free corrosion resistant mechanical parts, especially pitting corrosion resistant mechanical parts.

Disclosure of Invention

The invention aims to provide a wire rod for a spheroidizing annealing-free corrosion-resistant fastener and a preparation method thereof, which can improve the atmospheric corrosion resistance of a material on the basis of a conventional fastener, can avoid the spheroidizing annealing step, is directly used for drawing and cold heading, and overcomes the defects of the conventional product.

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

the invention relates to an annealing-free corrosion-resistant wire rod for mechanical parts, which comprises the following chemical components in percentage by mass: 0.35 to 0.42 percent of C, 0.20 to 0.45 percent of Si, 030 to 0.60 percent of Mn, 1.35 to 1.65 percent of Cr, 0.07 to 1.10 percent of Al, 0.15 to 0.25 percent of Mo, less than or equal to 0.020 percent of S, less than or equal to 0.020 percent of P, less than or equal to 0.0020 percent of O, less than or equal to 0.0040 percent of N, and the balance of Fe and unavoidable impurities.

Further, the specific chemical components are as follows: 0.38% of C, 0.25% of Si, 0.45% of Mn, 0.85% of Al, 0.19% of Mo, 1.50% of Cr, 0.010% of S, 0.012% of P, 15ppm of O, 48ppm of N and the balance of Fe and unavoidable impurities.

Further, the specific chemical components are as follows: 0.39% of C, 0.30% of Si, 0.47% of Mn, 0.90% of Al, 0.18% of Mo, 1.52% of Cr, 0.010% of S, 0.012% of P, 15ppm of O, 48ppm of N and the balance of Fe and unavoidable impurities.

Further, the specific chemical components are as follows: 0.40% of C, 0.35% of Si, 0.50% of Mn, 0.93% of Al, 0.22% of Mo, 1.51% of Cr, 0.010% of S, 0.012% of P, 15ppm of O, 48ppm of N and the balance of Fe and unavoidable impurities.

A preparation method of a wire rod for an annealing-free corrosion-resistant mechanical part comprises the steps of converter or electric furnace smelting, external refining, billet continuous casting, high-speed wire large coil rolling and controlled cooling which are sequentially carried out; wherein:

the cooling control procedure adopts the stelmor line cooling and the PF stacking cooling, and the spinning temperature or the coil collecting temperature, the number of fans and the air quantity before entering the heat preservation cover and the roller way speed are controlled, so that the temperature entering the heat preservation cover is 760-800 ℃, and the residence time in the heat preservation cover is more than or equal to 20min.

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

the wire rod for the spheroidizing annealing-free corrosion-resistant mechanical part is prepared by adopting reasonable component proportion and rolling process, spheroidizing annealing or softening annealing treatment before drawing or before cold heading can be avoided in the process of producing and manufacturing the tight mechanical part, the degree of environmental pollution is reduced, the labor intensity of workers can be lightened, the production cost is reduced, and the wire rod has the aim of good cold formability.

The corrosion resistance of the mechanical parts is improved by adding chemical elements such as Cr, mo and the like with corrosion resistance, particularly the pitting corrosion resistance of the mechanical parts which are frequently exposed in a corrosion atmosphere is improved, and the delayed fracture resistance of the mechanical parts is improved.

Al element is added and is dissolved in ferrite in a solid solution mode, so that the low-temperature toughness of the wire rod can be remarkably improved; the addition of a small amount of Mo can improve the temper brittleness of the wire rod;

Detailed Description

The invention will be further illustrated by the following examples

The production process flow of the corrosion-resistant alloy structural steel wire rod is conventional converter one-furnace external refining adjustment chemical composition and temperature one-billet continuous casting one-high line rolling one-cooling control.

Example 1

According to the chemical composition range required by the technology in the invention, a 110t converter is adopted, and after refining and continuous casting, the corrosion-resistant alloy structural steel wire rod with the following composition is smelted, and the specific chemical compositions are as follows: 0.38% of C, 0.25% of Si, 0.45% of Mn, 0.85% of Al, 0.19% of Mo, 1.50% of Cr, 0.010% of S, 0.012% of P, 15ppm of O, 48ppm of N and the balance of (%) Fe, wherein the rolling specification is phi 10mm, the stelmor is adopted for controlling cooling, the spinning temperature is controlled to 860 ℃,1 fan is started, the blowing volume is 50%, the heat preservation covers are separated by three, slow cooling is carried out, and the roller way time is 25min.

The surface quality of the rolled middle wire rod is good, the structure is a small amount of pearlite of typical ferrite, the rolled wire rod is subjected to a 1/3 cold heading test, each sample is tested in each batch, no cracking occurs, the tensile strength of the detected wire rod is 1020MPa, the area reduction rate is 15%, and the elongation rate is 45%.

Example 2

Adopting a 150t converter, refining and continuously casting to obtain the corrosion-resistant cold-heading steel wire rod with the following components, wherein the specific chemical components are as follows: 0.39% of C, 0.30% of Si, 0.47% of Mn, 0.90% of Al, 0.18% of Mo, 1.52% of Cr, 0.010% of S, 0.012% of P, 15ppm of O, 48ppm of N and the balance of (%) Fe, wherein the rolling specification is phi 10mm, the stelmor is adopted for controlling cooling, the spinning temperature is controlled to 860 ℃,1 fan and 2 fans are started, the blowing volume is 50%, the heat preservation cover is separated by three, slow cooling is carried out, and the roller way time is 20min.

The surface quality of the rolled middle wire rod is good, the structure is ferrite and a small amount of pearlite, the rolled wire rod is subjected to a 1/3 cold heading test, 12 samples are inspected in each batch, no cracking occurs, the tensile strength of the detected wire rod is 1150MPa, the area reduction rate is 12%, and the elongation rate is 38%.

Example 3

The 120t converter is adopted, and the following components are smelted after refining and continuous casting, namely the steel wire rods for corrosion-resistant mechanical parts are prepared by the following chemical components: 0.40% of C, 0.35% of Si, 0.50% of Mn, 0.93% of Al, 0.22% of Mo, 1.51% of Cr, 0.010% of S, 0.012% of P, 15ppm of O, 48ppm of N and the balance of (%) Fe, wherein the rolling specification is phi 10mm, the stelmor is adopted for controlling cooling, the spinning temperature is controlled to 820 ℃, the fans are fully closed, the heat preservation covers are fully closed, slow cooling is carried out, and the roller way time is 30min.

The surface quality of the rolled middle wire rod is good, the structure is ferrite and a small amount of pearlite, the rolled wire rod is subjected to a 1/3 cold heading test, 12 samples are inspected in each batch, no cracking occurs, the tensile strength of the detected wire rod is 970MPa, the area reduction rate is 20%, and the elongation rate is 45%.

The chemical compositions (mass percent) of the examples, the balance being Fe and unavoidable impurities, are shown in the following table:

table 2 shows the set of stell lines, the number of fans and the opening degree.

Scheme one:

stelmor line setting: number and opening degree of fans

The heat preservation covers are separated by one third, and 50% of the No. 1 fan.

Scheme II:

stelmor line setting: number and opening degree of fans

The heat preservation covers are separated by 50% of fans No. 1 and No. 2.

Scheme III:

stelmor line setting: number and opening degree of fans

The heat preservation cover is totally closed, and the fan is totally closed.

The above embodiments are only illustrative of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention, and various modifications and improvements made by those skilled in the art to the technical solutions of the present invention should fall within the protection scope defined by the claims of the present invention without departing from the design spirit of the present invention.

Claims (5)

1. The wire rod for the annealing-free corrosion-resistant mechanical part is characterized by comprising the following chemical components in percentage by mass: 0.35 to 0.42 percent of C, 0.20 to 0.45 percent of Si, 030 to 0.60 percent of Mn, 1.35 to 1.65 percent of Cr, 0.07 to 1.10 percent of Al, 0.15 to 0.25 percent of Mo, less than or equal to 0.020 percent of S, less than or equal to 0.020 percent of P, less than or equal to 0.0020 percent of O, less than or equal to 0.0040 percent of N, and the balance of Fe and unavoidable impurities.

2. The wire rod for annealing-free corrosion resistant mechanical parts according to claim 1, wherein the specific chemical composition is as follows: 0.38% of C, 0.25% of Si, 0.45% of Mn, 0.85% of Al, 0.19% of Mo, 1.50% of Cr, 0.010% of S, 0.012% of P, 15ppm of O, 48ppm of N and the balance of Fe and unavoidable impurities.

3. The wire rod for annealing-free corrosion resistant mechanical parts according to claim 1, wherein the specific chemical composition is as follows: 0.39% of C, 0.30% of Si, 0.47% of Mn, 0.90% of Al, 0.18% of Mo, 1.52% of Cr, 0.010% of S, 0.012% of P, 15ppm of O, 48ppm of N and the balance of Fe and unavoidable impurities.

4. The wire rod for annealing-free corrosion resistant mechanical parts according to claim 1, wherein the specific chemical composition is as follows: 0.40% of C, 0.35% of Si, 0.50% of Mn, 0.93% of Al, 0.22% of Mo, 1.51% of Cr, 0.010% of S, 0.012% of P, 15ppm of O, 48ppm of N and the balance of Fe and unavoidable impurities.

5. The method for producing a wire rod for annealing-free corrosion resistant mechanical parts according to any one of claims 1 to 4, comprising the steps of converter or electric furnace smelting, external refining, billet continuous casting, high-line large-coil rolling and controlled cooling which are sequentially carried out; wherein:

the cooling control procedure adopts the stelmor line cooling and the PF stacking cooling, and the spinning temperature or the coil collecting temperature, the number of fans and the air quantity before entering the heat preservation cover and the roller way speed are controlled, so that the temperature entering the heat preservation cover is 760-800 ℃, and the residence time in the heat preservation cover is more than or equal to 20min.