CN111187976A - New high-strength heat-resistant steel material - Google Patents

Abstract

The invention provides a new high-strength heat-resistant steel material which comprises the following components in percentage by weight: 27.0-28.0% of Cr, 1.50-2.50% of Mn, 0.20-0.35% of N, 0.30-0.40% of C, 8.00-9.00% of Ni, 1.30-1.70% of Si, less than or equal to 0.030% of S, less than or equal to 0.040% of P, and the balance of Fe; the new high-strength heat-resistant steel material can be widely applied to large-scale cement dry-process production lines, has excellent corrosion resistance and tensile resistance, increases the operation period of production equipment, reduces the production cost and improves the economic benefit.

Description

New high-strength heat-resistant steel material

Technical Field

The invention relates to a heat-resistant steel material, in particular to a new high-strength heat-resistant steel material which is widely applied in the building material industry.

Background

With the rapid development of global industry, resource problems are seriously brought to people, so that energy conservation and consumption reduction are great directions for industrial development in China, the maximization of profits is a main direction pursued by enterprises, and the reduction of environmental pollution in the production process is social responsibility which the enterprises should play. With the rapid development of building material industry and cement industry in China and the replacement of accessories in the production process, the market demand of high-strength heat-resistant steel products is greatly increased, such as suspension preheater inner cylinder hanging pieces, rotary kiln head and kiln tail protection plates, grate cooler grate plates and the like, the castings are contacted with high-temperature gas and corrosive materials for a long time, even if the castings are oxidized and corroded by high temperature of 1200 ℃ and are also worn by scouring of high-temperature materials, the use conditions are very severe, and therefore the performance of steel products directly determines the running stability of equipment such as cement heat engineering and the like.

At present, the inner cylinder of the preheater of main equipment in domestic cement production lines is generally made of high-chromium-nickel heat-resistant steel, such as the conventional material (ZG 40Cr25Ni 20) and the like. Because the heat-resistant steel products mostly adopt high-nickel, chromium and other precious metals as main raw materials and also adopt a large amount of auxiliary materials, the defects that the price cost of steel is higher, the heat resistance and wear resistance are poorer, the service life of equipment parts is short, the stability is poor, the application of complex auxiliary materials is easy to cause environmental pollution, the production cost is finally further increased and the like exist, and the development of a new high-strength heat-resistant steel material suitable for the wear-resistant and heat-resistant working condition conditions of equipment such as cement thermal engineering and the like is urgent and important.

Disclosure of Invention

The invention aims to provide a new high-strength heat-resistant steel material, which solves the problems of short service life, poor oxidation resistance and abrasion resistance of steel products in a high-temperature environment and environmental pollution in a casting process caused by the use of auxiliary materials.

In order to achieve the purpose, the invention provides a new high-strength heat-resistant steel material which comprises the following components in percentage by weight: 27.0 to 28.0 percent of Cr, 1.50 to 2.50 percent of Mn, 0.20 to 0.35 percent of N, 0.30 to 0.40 percent of C, 8.00 to 9.00 percent of Ni, 1.30 to 1.70 percent of Si, less than or equal to 0.030 percent of S, less than or equal to 0.040 percent of P, and the balance of Fe.

The alloy consists of Cr 27.3-27.6 wt%, Mn 1.6-2.00 wt%, N0.25-0.30 wt%, C0.33-0.36 wt%, Ni 8.10-8.60 wt%, Si 1.40-1.60 wt%, S not more than 0.030 wt%, P not more than 0.040 wt% and Fe for the rest.

The function of properly amplifying the content of Mn element: so as to improve the temperature resistance and enhance the corrosion resistance at high temperature. The function of amplifying the content of the Cr element is as follows: so as to improve the high temperature resistance, the durability and the corrosion resistance. The function of amplifying the content of the N element in a proper amount is as follows: so as to improve the durability, high temperature resistance and corrosion resistance. Through the adjustment of the content of the elements, a, the result of a high-temperature friction and wear comparison test shows that: under the conditions of high temperature of 600 ℃, 3.3N or 5.3N, the friction coefficient and the specific wear rate of the invention are both smaller than those of the prior material ZG40Cr25Ni20, and under the condition of loading of 5.3N, the specific wear rate of the invention is more obvious smaller than that of the prior material ZG40Cr25Ni20, and the specific wear rates of the invention and the prior material are respectively 0.00015mm3N1m1 and 0.0002 mm3N1m 1. b. The mechanical property and the metallographic structure comparison observation at normal temperature show that: the tensile strength, yield strength and elongation of the existing material ZG40Cr25Ni20 in room temperature mechanical properties are respectively 421.7Mp, 273.8Mp and 8.3 percent which are slightly lower than the national standard GB8492-87, the indexes of the invention are 564.8Mp, 360.5Mp and 16.2 percent which completely reach the standard value of the national standard GB8492-87, and the content of the eutectic carbon compound in the material tissue of the invention is obviously higher than that in the existing material tissue through a light mirror and a scanning electron microscope picture, so the microhardness of the invention is higher than that of the existing material, and the quantity of the microshrinkage holes of the invention is obviously more than that of the microshrinkage holes distributed in the existing material. c. The results of the high-temperature oxidation and high-temperature corrosion comparison test show that: after the high-temperature oxidation at 1000 ℃ for 100h, the high-temperature oxidation performance of the composite material and the prior material both follow the parabolic law of oxidation kinetics, and the parabolic linear velocity constants of the composite material are kp1=8.04 × 10-3mg2/cm4 × h (0-50 h), kp2=3.99 × 10-3mg2/cm4 × h (50-100 h) respectively; the existing material kp1=9.88 × 10-3mg2/cm4 × h (0-50 h), and kp2=4.78 × 10-3mg2/cm4 × h (50-100 h), so that the oxygen oxidation resistance of the invention is stronger than that of the existing material, and the high-temperature oxidation resistance is better; compared with the high-temperature salt corrosion performance, the existing material is corroded into a sheet of about 1mm at 100h, 1000 ℃ and the end of NaCl corrosion, the thickness of the sample of the invention is obviously thicker than that of the existing material, and the high-temperature salt corrosion resistance of the new heat-resistant material is obviously stronger than that of the existing material; compared with the durability at high temperature under the conditions of 900 ℃ and stress of 80Mp or 100Mp, the durability of the material is respectively 17 minutes and 5 minutes, and the durability of the material is respectively 5 hours and 2 hours.

The invention has the beneficial effects that:

(1) The novel high-strength heat-resistant steel material can be widely applied to large-scale cement dry-process production lines, the corrosion resistance is superior to that of the existing ZG40Cr25Ni20 material, the operation period of the production line is prolonged, the production cost is reduced, the cost of the novel heat-resistant steel material only accounts for 53.87% of that of the existing ZG40Cr25Ni20 material, and the economic benefit is improved.

(2) The novel heat-resistant steel material greatly saves resources, is deficient in nickel resources in China, has large market demand and domestic gap, mostly depends on import, has low nickel content, and plays the roles of saving energy, reducing consumption and protecting limited resources of the earth.

(3) The casting process of the material is beneficial to environmental protection, and has the win-win effect of economic benefit and social benefit.

Detailed Description

In order to enhance the understanding of the present invention, the present invention will be further described with reference to the following examples, which are only for the purpose of illustrating the present invention and are not to be construed as limiting the scope of the present invention.

Example 1

The new high-strength heat-resistant steel material comprises the following components in percentage by weight: 27.3% Cr, 1.53% Mn, 0.25% N, 0.31% C, 8.10% Ni, 1.40% Si, 0.010% S, 0.015% P, and the balance Fe.

Mechanical properties after quenching and tempering: tensile strength (Mpa): 560.8, yield (Mpa): 332.4, respectively; elongation after fracture (%): 12.6.

example 2

The new high-strength heat-resistant steel material comprises the following components in percentage by weight: 27.6% Cr, 1.90% Mn, 0.27% N, 0.34% C, 8.60% Ni, 1.56% Si, 0.015% S, 0.020% P, and the balance Fe.

Mechanical properties after quenching and tempering: tensile strength (Mpa): 562.8, yield (Mpa): 347.3, respectively; elongation after fracture (%): 14.9. example 3 a new high-strength heat-resistant steel material is composed of the following components in percentage by weight: 27.5% Cr, 2.49% Mn, 0.34% N, 0.39% C, 8.97% Ni, 1.60% Si, 0.030% S, 0.040% P, and the balance Fe.

Mechanical properties after quenching and tempering: tensile strength (Mpa): 564.8, yield (Mpa): 360.5; elongation after fracture (%): 16.2.

Claims (2)

1. a new high-strength heat-resistant steel material is characterized in that: the new high-strength heat-resistant steel material comprises the following components in percentage by weight: 27.0 to 28.0 percent of Cr, 1.50 to 2.50 percent of Mn, 0.20 to 0.35 percent of N, 0.30 to 0.40 percent of C, 8.00 to 9.00 percent of Ni, 1.30 to 1.70 percent of Si, less than or equal to 0.030 percent of S, less than or equal to 0.040 percent of P, and the balance of Fe.

2. A new material of high strength heat resistant steel according to claim 1, characterized in that: the alloy consists of Cr 27.3-27.6 wt%, Mn 1.6-2.00 wt%, N0.25-0.30 wt%, C0.33-0.36 wt%, Ni 8.10-8.60 wt%, Si 1.40-1.60 wt%, S not more than 0.030 wt%, P not more than 0.040 wt% and Fe for the rest.