CN103014548A - Alloy steel and preparation method thereof - Google Patents

Abstract

The invention relates to alloy steel. The alloy steel comprises the following components in percentage by weight: 0.45-0.52% of C, 0.24-0.25% of Si, 0.3-0.35% of Mn, 0.3-0.5% of Cr, 0.6-1.0% of Ni, 0.03% of Mo, 0.06% of Co, 0.08% of V, 0.6% of W, 0.0001% of Ti, 0.003% of B and the balance of Fe. Massive pearly-lustre bases are obtained by virtue of a normalizing process, and salt bath isothermal quenching is selected, so that austenite of the alloy steel is converted into lower bainite, and the hardness, abrasion resistance and surface heat resistance of alloy are greatly improved.

Description

A kind of steel alloy and preparation method thereof

Technical field

The present invention relates to metallic substance, especially relate to a kind of steel alloy and preparation method thereof.

Background technology

The matching with automobile engine parts not only have higher requirement in structural strength and function, while no less important on mechanical workout, and such requirement is not only and is satisfied the primary condition that automobile uses, and also is the safe and reliable guarantee that increases the service life simultaneously.

Search out a kind of raising hardness and wear resisting property, it is extremely important that the steel alloy of the middle low levels that the piece surface resistance toheat is high simultaneously just shows.The contriver relies on for many years practice and the theoretical experience of this area, proposes a kind of brand-new steel alloy prescription, and this prescription can solve the shortcoming of existing production auto parts machinery steel.

Summary of the invention

The purpose of this invention is to provide a kind of steel alloy that can overcome hardness, wear resisting property and Thermal Resistant Surface performance deficiency in the existing production trolley part steel.

The present invention seeks to be achieved through the following technical solutions:

A kind of steel alloy, the weight percent of this steel alloy is: the carbon of 0.45-0.52%, the silicon of 0.24-0.25%, the manganese of 0.3-0.35%, the chromium of 0.3-0.5%, the nickel of 0.6-1.0%, 0.03% molybdenum, 0.06% cobalt, 0.08% alum, 0.6% tungsten, 0.0001% titanium, 0.003% boron surplus is iron.

The preparation method of described steel alloy may further comprise the steps:

1) according to weight percent is the carbon of 0.45-0.52%, the silicon of 0.24-0.25%, the manganese of 0.3-0.35%, the chromium of 0.3-0.5%, the nickel of 0.6-1.0%, 0.03% molybdenum, 0.06% cobalt, 0.08% alum, 0.6% tungsten, 0.0001% titanium, 0.003% boron surplus are that iron is prepared burden;

2) prepare steel alloy by the medium-frequency induction furnace melting;

3) steel alloy is carried out normalizing and means of isothermal quenching; In two stages isothermal quenching of described quenching, the fs adopts 230 ± 20 ℃ of salt bath austemperings to process to 500-550 ℃, and quenching velocity remains on 20-25 ℃ of p.s.; Subordinate phase is aqueous solution quench, and the aqueous solution remains on 75-80 ℃, and quenching velocity remains on 25-30 ℃ of per second, and quenching temperature is to 130-150 ℃; Then temper, tempering temperature be 180-220 ℃ and be incubated 2 hours, then naturally cooling.

Above-mentioned steel alloy preparation method, its Medium Alloy Steel is by normalizing and means of isothermal quenching.Obtain so on the one hand higher pearlite matrix, thinning microstructure, hardness and the wear resisting property of raising material; On the other hand, by remaining on for a long time the isothermal quenching in Lower Bainite Transformation district, make alloy realize austenitic isothermal transformation, obtain the lower bainite tissue.

The invention has the beneficial effects as follows:

By a large amount of pearly-lustre matrix of normalizing Procedure Acquisition, and pass through to select 230 ± 20 ℃ salt bath austempering, make the austenitic transformation of steel alloy become the lower bainite tissue, so that alloy rigidity, wear resisting property and Thermal Resistant Surface performance all are greatly improved.

Embodiment

Below explain the present invention by specific embodiment, should be understood that specific embodiments of the invention only can be used for explaining the present invention and can not be used for being interpreted as limitation of the present invention.

Embodiment one

A kind of steel alloy, the weight percent of this steel alloy is: 0.45% carbon, 0.24% silicon, 0.3% manganese, 0.3% chromium, 0.6% nickel, 0.03% molybdenum, 0.06% cobalt, 0.08% alum, 0.6% tungsten, 0.0001% titanium, 0.003% boron surplus is iron.

The preparation method of described steel alloy may further comprise the steps:

1) according to weight percent is the carbon of 0.45-0.52%, the silicon of 0.24-0.25%, the manganese of 0.3-0.35%, the chromium of 0.3-0.5%, the nickel of 0.6-1.0%, 0.03% molybdenum, 0.06% cobalt, 0.08% alum, 0.6% tungsten, 0.0001% titanium, 0.003% boron surplus are that iron is prepared burden;

2) prepare steel alloy by the medium-frequency induction furnace melting;

3) steel alloy is carried out normalizing and means of isothermal quenching; In two stages isothermal quenching of described quenching, the fs adopts 230 ± 20 ℃ of salt bath austemperings to process to 500-550 ℃, and quenching velocity remains on 20-25 ℃ of p.s.; Subordinate phase is aqueous solution quench, and the aqueous solution remains on 75-80 ℃, and quenching velocity remains on 25-30 ℃ of per second, and quenching temperature is to 130-150 ℃; Then temper, tempering temperature be 180-220 ℃ and be incubated 2 hours, then naturally cooling.

Above-mentioned steel alloy preparation method, its Medium Alloy Steel is by normalizing and means of isothermal quenching.Obtain so on the one hand higher pearlite matrix, thinning microstructure, hardness and the wear resisting property of raising material; On the other hand, by remaining on for a long time the isothermal quenching in Lower Bainite Transformation district, make alloy realize austenitic isothermal transformation, obtain the lower bainite tissue.

The cast alloy steel sample that obtains is done metallographic structure observe, find that it is organized as pearlitic structure and lower Bei Shi tissue.

The alloy that obtains is carried out hardness detect hardness detected value HRC55.

In following examples of the present invention, the cast alloy steel sample that obtains is done metallographic structure observe, find that all it is organized as pearlitic structure and lower Bei Shi tissue.

The alloy that obtains is carried out hardness detect hardness detected value HRC54-57.

In following examples of the present invention, the preparation method of steel alloy is all identical, and difference only is the composition of each element of low alloy steel, therefore in following embodiment, only describe steel alloy each element weight percent.

Embodiment two

A kind of steel alloy, the weight percent of this steel alloy is: 0.52% carbon, 0.25% silicon, 0.35% manganese, 0.5% chromium, 1.0% nickel, 0.03% molybdenum, 0.06% cobalt, 0.08% alum, 0.6% tungsten, 0.0001% titanium, 0.003% boron surplus is iron.

The alloy that obtains is carried out hardness detect hardness detected value HRC57.

Embodiment three

A kind of steel alloy, the weight percent of this steel alloy is: 0.50% carbon, 0.24% silicon, 0.32% manganese, 0.4% chromium, 0.8% nickel, 0.03% molybdenum, 0.06% cobalt, 0.08% alum, 0.6% tungsten, 0.0001% titanium, 0.003% boron surplus is iron.

According to the manufacturing processed manufacturing of embodiment one, the alloy that obtains is carried out hardness detect hardness detected value HRC62.

The cast alloy steel sample that obtains is done metallographic structure observe, find that its tissue major part is pearlitic structure and lower Bei Shi tissue.

When for the manufacture of the braking devices parts of automobile, preferred this embodiment.

The present invention is not limited to above-mentioned specific embodiment, and in the case of without departing from the present invention, those skilled in the art can make according to the present invention various corresponding changes, but these corresponding changes all should belong within the claimed scope of the present invention.

Claims (2)

1. steel alloy, it is characterized in that: the weight percent of this steel alloy is the carbon of 0.45-0.52%, the silicon of 0.24-0.25%, the manganese of 0.3-0.35%, the chromium of 0.3-0.5%, the nickel of 0.6-1.0%, 0.03% molybdenum, 0.06% cobalt, 0.08% alum, 0.6% tungsten, 0.0001% titanium, 0.003% boron surplus is iron.

2. the preparation method of a steel alloy may further comprise the steps:

1) according to weight percent is the carbon of 0.45-0.52%, the silicon of 0.24-0.25%, the manganese of 0.3-0.35%, the chromium of 0.3-0.5%, the nickel of 0.6-1.0%, 0.03% molybdenum, 0.06% cobalt, 0.08% alum, 0.6% tungsten, 0.0001% titanium, 0.003% boron surplus are that iron is prepared burden;

2) prepare steel alloy by the medium-frequency induction furnace melting;

3) steel alloy is carried out normalizing and means of isothermal quenching; In two stages isothermal quenching of described quenching, the fs adopts 230 ± 20 ℃ of salt bath austemperings to process to 500-550 ℃, and quenching velocity remains on 20-25 ℃ of p.s.; Subordinate phase is aqueous solution quench, and the aqueous solution remains on 75-80 ℃, and quenching velocity remains on 25-30 ℃ of per second, and quenching temperature is to 130-150 ℃; Then temper, tempering temperature be 180-220 ℃ and be incubated 2 hours, then naturally cooling.