阅读说明：本技术 一种高强度高韧性锻压件及其制备方法 (High-strength and high-toughness forged piece and preparation method thereof ) 是由 李久宁 于 2019-10-14 设计创作，主要内容包括：本发明公开了一种高强度高韧性锻压件,按重量百分比计由如下组分组成：C的含量为0.1％-0.3％,Cr的含量为11.0％-18.0％,Mn的含量为0.8％-1.5％,Si的含量为1.5％-2.O％,V的含量为0.4％-0.6％,Ni的含量为0.1％-0.4％,Ti的含量小于0.04％,P的含量小于0.02％,S的含量小于为0.02％,余量为铁和不可避免的杂质元素。并且公开了其制备方法。本发明能够提高锻压件的抗拉强度、疲劳强度的同时提高其韧性,同时得到的锻压件还具有较好的耐腐蚀性。(The invention discloses a high-strength high-toughness forged piece, which comprises the following components in percentage by weight: 0.1 to 0.3 percent of C, 11.0 to 18.0 percent of Cr, 0.8 to 1.5 percent of Mn, 1.5 to 2O percent of Si, 0.4 to 0.6 percent of V, 0.1 to 0.4 percent of Ni, less than 0.04 percent of Ti, less than 0.02 percent of P, less than 0.02 percent of S, and the balance of iron and inevitable impurity elements. And a method for preparing the same are disclosed. The invention can improve the tensile strength and fatigue strength of the forged and pressed piece and simultaneously improve the toughness of the forged and pressed piece, and the obtained forged and pressed piece also has better corrosion resistance.)

1. The high-strength high-toughness forged piece is characterized by comprising the following components in percentage by weight: 0.1 to 0.3 percent of C, 11.0 to 18.0 percent of Cr, 0.8 to 1.5 percent of Mn, 1.5 to 2O percent of Si, 0.4 to 0.6 percent of V, 0.1 to 0.4 percent of Ni, less than 0.04 percent of Ti, less than 0.02 percent of P, less than 0.02 percent of S, and the balance of iron and inevitable impurity elements.

2. A high strength, high toughness wrought product according to claim 1, characterized in that the content of C is 0.10-0.14%.

3. A high strength, high toughness wrought product according to claim 1, characterized in that the content of Cr is 6.4-6.8%.

4. A high strength, high toughness wrought product according to claim 1, characterized in that the content of Mn is 0.9-1.2%.

5. A high strength, high toughness wrought product according to claim 1, characterized in that the content of Si is 1.8% -2. O%.

6. A high strength, high toughness wrought product according to claim 1, characterized in that the content of V is 0.4-0.5%.

7. A method of producing a high-strength high-toughness forged part according to claim 1, characterized by comprising the steps of:

1) preparing raw materials according to the components and the burning loss of the forged piece in percentage by weight, putting the raw materials into an electric heating furnace in a vacuum environment for smelting, and casting into steel ingots in an argon protection mode, wherein the steel ingots comprise the following components in percentage by weight: 0.1 to 0.3 percent of C, 11.0 to 18.0 percent of Cr, 0.8 to 1.5 percent of Mn, 1.5 to 2O percent of Si, 0.4 to 0.6 percent of V, 0.1 to 0.4 percent of Ni, less than 0.04 percent of Ti, less than 0.02 percent of P, less than 0.02 percent of S, and the balance of iron and inevitable impurity elements.

2) Forging the obtained steel ingot by using a forging press, wherein the forging starting temperature is 1100 +/-20 ℃, the forging finishing temperature is 900 ℃ and 20 ℃, the forging ratio is 1.2-1.5, and air cooling is carried out after forging;

3) placing the forged piece into a heat preservation furnace, preserving heat at 950-1050 ℃ for 2-4h, then placing the forged piece into a combined quenching device, rapidly cooling at 950 ℃, 900 ℃ and 860 ℃ in sequence to realize triple quenching, and then placing the forged piece into a subcritical quenching device to perform subcritical quenching treatment;

4) putting the forged and pressed piece into a tempering and cooling chamber, tempering for 2h at 200-400 ℃, and then naturally cooling.

8. A method of manufacturing a high strength and high toughness wrought product according to claim 7, characterized in that the tempering temperature of the wrought product is 270 ℃.

Technical Field

The invention relates to the field of forged parts, in particular to a high-strength high-toughness forged part and a preparation method thereof.

Background

As is known, if the strength of parts is improved, a series of effects of light structure of parts and even the whole machine, high efficiency of equipment operation, energy conservation and the like can be achieved, and the improvement of the strength of forgings can bring obvious benefits. Because the size of forging is generally great, the production process has the particularity, and the effect is more obvious to a certain extent.

Heretofore, in general, alloy elements are introduced into a forged part by alloy strengthening to form a solid solution to enhance the metal strength, and for example, patent application No. 2004100967957 discloses an alloy steel produced by the TMCP + RPC + SQ method to obtain a high-strength steel with a tensile strength of 800MPa class, but the forged part subjected to alloy strengthening has reduced toughness and is difficult to meet the use requirements of specific occasions.

Disclosure of Invention

The technical problems to be solved by the invention are as follows: the existing forged piece is difficult to improve the strength performance of metal and ensure the toughness of the metal at the same time in the processing.

In order to achieve the purpose, the invention provides the following technical scheme:

a high-strength high-toughness forged piece comprises the following components in percentage by weight: 0.1 to 0.3 percent of C, 11.0 to 18.0 percent of Cr, 0.8 to 1.5 percent of Mn, 1.5 to 2O percent of Si, 0.4 to 0.6 percent of V, 0.1 to 0.4 percent of Ni, less than 0.04 percent of Ti, less than 0.02 percent of P, less than 0.02 percent of S, and the balance of iron and inevitable impurity elements. Through reasonably adjusting the proportion of each element in the forged piece, the tensile strength, the fatigue strength and the toughness of the forged piece can be obviously improved, and meanwhile, the obtained forged piece also has better corrosion resistance.

Preferably, the content of C is 0.10% -0.14%.

Preferably, the content of Cr is 6.4% -6.8%.

Preferably, the Mn content is 0.9% to 1.2%.

Preferably, the content of Si is 1.8% -2. O%.

Preferably, the content of V is 0.4% to 0.5%.

A preparation method of a high-strength and high-toughness forged piece comprises the following steps:

1) preparing raw materials according to the components and the burning loss of the forged piece in percentage by weight, putting the raw materials into an electric heating furnace in a vacuum environment for smelting, and casting into steel ingots in an argon protection mode, wherein the steel ingots comprise the following components in percentage by weight: 0.1 to 0.3 percent of C, 11.0 to 18.0 percent of Cr, 0.8 to 1.5 percent of Mn, 1.5 to 2O percent of Si, 0.4 to 0.6 percent of V, 0.1 to 0.4 percent of Ni, less than 0.04 percent of Ti, less than 0.02 percent of P, less than 0.02 percent of S, and the balance of iron and inevitable impurity elements.

2) Forging the obtained steel ingot by using a forging press, wherein the forging starting temperature is 1100 +/-20 ℃, the forging finishing temperature is 900 ℃ and 20 ℃, the forging ratio is 1.2-1.5, and air cooling is carried out after forging;

3) placing the forged piece into a heat preservation furnace, preserving heat at 950-1050 ℃ for 2-4h, then placing the forged piece into a combined quenching device, rapidly cooling at 950 ℃, 900 ℃ and 860 ℃ in sequence to realize triple quenching, and then placing the forged piece into a subcritical quenching device to perform subcritical quenching treatment; the subcritical quenching is a quenching process of heating the hypoeutectoid steel to a certain temperature in a (a + y) two-phase region, preserving heat for a period of time, and then cooling by using a quenching medium, so as to improve the toughness of the steel and reduce the brittle transition temperature;

4) putting the forged and pressed piece into a tempering and cooling chamber, tempering for 2h at 200-400 ℃, and then naturally cooling.

Preferably, the tempering temperature of the wrought product in step 4) is 270 ℃.

The main functions of each chemical element are:

c is a main element determining the strength of steel, and a certain content of C is required for the steel to have a certain strength, but if the content of pearlite in the steel is too high, the ductile-brittle transition temperature of the steel increases, i.e., the low-temperature impact properties decrease.

Cr is a carbide-forming element which promotes the formation of ferrite, and can improve the strength and toughness of steel and improve the corrosion resistance of steel.

Mn can improve the strength and toughness of steel, and the increase of Mn content in low-carbon steel can obviously reduce the ductile-brittle transition temperature.

Si is a deoxidizing element in steel and can increase the strength of steel, and the toughness of steel is reduced when the Si content in steel is too high.

V can refine grains and improve the strength of the steel, and can reduce the ductile-brittle transition temperature of the steel within a certain content range.

The main role of Ni is that it changes the crystal structure of the steel, thereby improving properties such as plasticity, weldability and toughness.

Ti forms a compound with C, N primarily in steel to improve strength and hardness.

Compared with the prior art, the invention has the beneficial effects that: the forging and pressing piece has the advantages that the tensile strength and the fatigue strength of the forging and pressing piece can be improved, the toughness of the forging and pressing piece is improved, and the obtained forging and pressing piece has good corrosion resistance.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.