Welding method of high-strength wear-resistant steel

Abstract

The application discloses a high-strength wear-resistant steel welding method, which uses a welding wire with components in percentage by mass as follows: C 0.08-0.11%, Si 0.66-0.82%, Mn 1.85-2.30%, Ni 0.01-0.32%, S ≤0.02%, P ≤0.02%, Cr 0.02-0.04%, Cu 0.09-0.12%, and Mo 0.10-0.25%. The welding wire is applied to a high-strength wear-resistant steel welding process to perform CO2 gas shielded welding, and a three-pass welding process method is adopted, so that the Vickers hardness difference of a weld zone and a heat-affected zone can be controlled within 40, the service performance of a welded joint is improved, the welding requirement of the high-strength wear-resistant steel is met, the application field of the high-strength wear-resistant steel is expanded, and the rapid development of new equipment manufacturing industry can be promoted.

Description

Technical Field

[0001] This invention belongs to the field of welding technology, specifically relating to a welding method for high-strength wear-resistant steel. Background Technology

[0002] Construction machinery is an important component of the equipment manufacturing industry, referring to equipment used in mining and various engineering construction projects, such as excavators, loaders, bulldozers, various cranes, and hydraulic supports for coal mines. With the rapid development of my country's economy, the expansion of construction and resource development has led to a surge in demand for construction machinery. The construction machinery industry has become one of the fastest-growing and most promising sectors in machinery manufacturing, resulting in the rapid development of wear-resistant steel. As construction machinery gradually develops towards high performance, lightweight, and large-scale applications, its outer surface directly contacts materials such as sand and ore, bearing extremely complex loads. It is subjected not only to strong impacts and severe wear but also to periodic alternations. Therefore, the steel used must possess not only general strength and toughness but also wear resistance, impact resistance, fatigue resistance, and good weldability. With the increasingly widespread application of high-strength wear-resistant steel, the requirements for welding wires and welding methods used in welding this type of steel are also becoming higher. However, there are very few welding wires on the market that can meet the welding requirements of high-strength wear-resistant steel. In actual production, lower-grade welding wires are often used for welding. The performance of the steel structure after cladding with these welding wires using traditional welding processes cannot match that of high-strength wear-resistant steel in terms of hardness, strength, or wear resistance. This results in a large hardness difference between the weld zone and the heat-affected zone of the weld joint of high-strength wear-resistant steel, poor service performance, and failure to meet the welding requirements of high-strength wear-resistant steel. Therefore, it is urgent to develop a welding method for high-strength wear-resistant steel to further promote its application and popularization. Summary of the Invention

[0003] To overcome the shortcomings of the existing technology, this invention discloses a welding method for high-strength wear-resistant steel, which addresses the technical defects such as large hardness difference between the weld zone and heat-affected zone of the welded joint and poor service performance. The method is applicable to multi-layer and multi-pass welding of high-strength wear-resistant steel, and the weld formation is aesthetically pleasing. The Vickers hardness difference between the weld zone and heat-affected zone of the obtained welded joint is within 40.

[0004] To achieve the above-mentioned objective, this invention provides a welding method for high-strength wear-resistant steel. The welding wire used in this method, by mass percentage, comprises: C: 0.08–0.11%, Si: 0.66–0.82%, Mn: 1.85–2.30%, Ni: 0.01–0.32%, S: ≤0.02%, P: ≤0.02%, Cr: 0.02–0.04%, Cu: 0.09–0.12%, and Mo: 0.10–0.25%.

[0005] Adding 0.09–0.12% Cu and 0.10–0.25% Mo to the welding wire can strengthen the weld and improve its toughness and corrosion resistance. However, excessive Cu content can cause weld embrittlement, so the Cu content is limited to the range of 0.09–0.12%. Mo can refine the grain size in the weld zone and improve the hardenability of the weld metal. However, excessive Mo content can easily lead to weld oxidation, so the Mo content is limited to the range of 0.10–0.25%.

[0006] CO2 gas shielded welding was used for welding. The thickness of the high-strength wear-resistant steel was 8 mm. The chemical composition of the high-strength wear-resistant steel, by weight percentage, included: C: 0.12-0.20%, Si: 0.16-0.22%, Mn: 1.00-1.80%, Ni: 0.20-0.35%, S: ≤0.03%, P: ≤0.04%, Nb: 0.02-0.05%, Mo: 0.10-0.35%, Als: 0.015-0.035%, Ti: 0.30-0.50%, with the balance being Fe and unavoidable impurities. The tensile strength of the high-strength wear-resistant steel was 670-750 MPa, the yield strength was 530-560 MPa, and the Vickers hardness of the base material was 210-220 HV.

[0007] The aforementioned welding wire is used to perform a three-pass welding process on high-strength wear-resistant steel. The three-pass welding process includes: a first pass with a welding current of 180–210 A, a welding voltage of 21–23 V, and a welding speed of 10–12 cm / min; a second pass with a welding current of 120–135 A, a welding voltage of 18.5–19.0 ​​V, and a welding speed of 18–20 cm / min; and a third pass with a welding current of 130–140 A, a welding voltage of 19.5–20.0 V, and a welding speed of 13–15 cm / min.

[0008] An application of the above welding method in the mechanical engineering industry.

[0009] Compared with the prior art, the beneficial effects of the present invention are as follows: by using the above-mentioned welding wire and welding process to weld high-strength wear-resistant steel, the difference in Vickers hardness between the weld zone and the heat-affected zone can be controlled within 40, which is beneficial to improving the service performance of the welded joint. Attached Figure Description

[0010] Figure 1 Microscopic images of the microstructure of the weld zone in the welding process of Example 1;

[0011] Figure 2 Microscopic images of the microstructure of the second-pass weld zone in the welding process of Example 1;

[0012] Figure 3 These are microscopic images of the microstructure of the three-pass weld zone in the welding process of Example 1. Detailed Implementation

[0013] The present invention will be further described below with reference to specific embodiments, but this does not limit the invention in any way. To avoid redundancy, unless otherwise specified, all raw materials used in the following embodiments are commercially available, and all methods used are conventional methods unless otherwise specified. The Vickers hardness difference was tested according to standard GB / T 4340.1-2009 Metallic Materials Vickers Hardness Test Part 1: Test Methods.

[0014] The chemical composition of high-strength wear-resistant steel, by weight percentage, includes C: 0.12–0.20%, Si: 0.16–0.22%, Mn: 1.00–1.80%, Ni: 0.20–0.35%, S: ≤0.03%, P: ≤0.04%, Nb: 0.02–0.05%, Mo: 0.10–0.35%, Als: 0.015–0.035%, Ti: 0.30–0.50%, with the balance being Fe and unavoidable impurities. High-strength wear-resistant steel has a tensile strength of 670–750 MPa, a yield strength of 530–560 MPa, and a Vickers hardness of 210–220 HV.

[0015] Example

[0016] A welding method for high-strength wear-resistant steel, wherein the welding wire composition meets the following mass percentage requirements: C: 0.08–0.11%, Si: 0.66–0.82%, Mn: 1.85–2.30%, Ni: 0.01–0.32%, S: ≤0.02%, P: ≤0.02%, Cr: 0.02–0.04%, Cu: 0.09–0.12%, Mo: 0.10–0.25%.

[0017] The aforementioned high-strength wear-resistant steel was welded using the welding wire in three passes. The three-pass welding process included: a first pass with a welding current of 180–210 A, a welding voltage of 21–23 V, and a welding speed of 10–12 cm / min; a second pass with a welding current of 120–135 A, a welding voltage of 18.5–19.0 ​​V, and a welding speed of 18–20 cm / min; and a third pass with a welding current of 130–140 A, a welding voltage of 19.5–20.0 V, and a welding speed of 13–15 cm / min.

[0018] High-strength wear-resistant steel was welded using carbon dioxide gas shielded welding. The welding wire composition, welding process, and Vickers hardness difference between the weld zone and heat-affected zone of the weld joint are shown in Table 1.

[0019] Comparative Example

[0020] The welding process is two passes, with the same welding technique used in each pass. The welding current is 180-210A, the welding voltage is 21-23V, and the welding speed is 10-12cm / min.

[0021] Table 1. Test results of chemical composition of welding wire, welding process parameters, and Vickers hardness difference.

[0022]

[0023] The welding wire provided by this invention has good fluidity, which is beneficial to weld formation. The three-pass welding method provided can effectively control the interpass temperature and reduce the overall heat input of the weld joint, thereby controlling the microstructure content and hardness difference of the weld joint, which is beneficial to improving the overall performance of the weld joint.

[0024] For anyone skilled in the art, many possible variations and modifications can be made to the technical solutions of this invention, or equivalent embodiments can be modified based on the disclosed technical content, without departing from the scope of the technical solutions of this invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this invention without departing from the content of the technical solutions of this invention should still fall within the protection scope of the technical solutions of this invention.

Claims

1. A welding method for high-strength wear-resistant steel, characterized in that, The welding wire composition used in the method, by mass percentage, is: C: 0.08–0.11%, Si: 0.73–0.82%, Mn: 2.1–2.30%, Ni: 0.01–0.32%, S: ≤0.02%, P: ≤0.02%, Cr: 0.02–0.04%, Cu: 0.10–0.12%, Mo: 0.18–0.25%. The welding wire is used to perform a three-pass welding process; The three-pass welding process includes: the first pass welding process with welding current of 180-210A, welding voltage of 21-23V, and welding speed of 10-12cm / min; the second pass welding process with welding current of 120-135A, welding voltage of 18.5-19.0V, and welding speed of 18-20cm / min; and the third pass welding process with welding current of 130-140A, welding voltage of 19.5-20.0V, and welding speed of 13-15cm / min.

2. The welding method according to claim 1, characterized in that, The chemical composition of the high-strength wear-resistant steel, by weight percentage, includes C: 0.12–0.20%, Si: 0.16–0.22%, Mn: 1.00–1.80%, Ni: 0.20–0.35%, S: ≤0.03%, P: ≤0.04%, Nb: 0.02–0.05%, Mo: 0.10–0.35%, Als: 0.015–0.035%, Ti: 0.30–0.50%, with the balance being Fe and unavoidable impurities.

3. The welding method according to claim 2, characterized in that, The high-strength wear-resistant steel has a tensile strength of 670-750 MPa, a yield strength of 530-560 MPa, and a Vickers hardness of 210-220 HV.

4. The application of the welding method as described in any one of claims 1-3 in the mechanical engineering industry.

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