阅读说明：本技术 一种高强混合钢十字接头埋弧焊焊接方法 (Submerged-arc welding method for high-strength hybrid steel cross joint ) 是由 狄谨 潘延晖 张茜 秦凤江 于 2021-09-09 设计创作，主要内容包括：本发明公开了一种高强混合钢十字接头埋弧焊焊接方法,涉及高强混合钢焊接技术领域,包括以下步骤：立板和横板皆采用高强混合钢,在所述横板待焊接的一端开设坡口；对立板及横板进行焊前预热,且预热温度温度不低于60℃；采用低强匹配型焊丝对焊道进行打底；采用低强匹配型焊丝对打底后的焊道进行填充；采用低强匹配型焊丝对填充后的焊道进行盖面。通过本发明的设置以实现高强混合钢埋弧焊焊接工艺在钢结构建筑上的推广应用。(The invention discloses a submerged-arc welding method for a high-strength mixed steel cross joint, which relates to the technical field of high-strength mixed steel welding and comprises the following steps: the vertical plate and the transverse plate are both made of high-strength mixed steel, and a groove is formed at one end to be welded of the transverse plate; preheating the vertical plate and the transverse plate before welding, wherein the preheating temperature is not lower than 60 ℃; bottoming the welding bead by using a low-strength matching type welding wire; filling the bottomed welding bead by using a low-strength matching type welding wire; and adopting a low-strength matching type welding wire to cover the filled welding bead. The device realizes the popularization and the application of the submerged arc welding process of the high-strength mixed steel on the steel structure building.)

1. A submerged arc welding method for a high-strength hybrid steel cross joint is characterized by comprising the following steps:

s1: pretreatment of welded steel: the vertical plate and the transverse plate are both made of high-strength mixed steel, and a groove is formed at one end to be welded of the transverse plate;

s2: preheating before welding: preheating the vertical plate and the transverse plate before welding, wherein the preheating temperature is not lower than 60 ℃;

s3: backing up a weld joint: bottoming the welding bead by using a low-strength matching type welding wire;

s4: filling a welding seam: filling the bottomed welding bead by using a low-strength matching type welding wire;

s5: and (4) cover surface welding seam: and adopting a low-strength matching type welding wire to cover the filled welding bead.

2. The submerged arc welding method for the high-strength hybrid steel cross joint according to claim 1, characterized in that the cross section of the transverse plate groove is of a trapezoidal structure, the included angle between the first side wall of the trapezoidal structure and the vertical plate is 30-60 degrees, the included angle between the second side wall of the trapezoidal structure and the vertical plate is 30-60 degrees, and the width of the upper bottom surface of the trapezoidal structure is 4-5 mm.

3. The submerged arc welding method for the high-strength hybrid steel cruciform joint according to claim 1, characterized in that the backing weld step comprises: the welding current is 500-550A, the welding voltage is 30-33V, the welding speed is 35-40 cm/min, and the heat input is 22.5-31.1 kJ/cm.

4. The submerged arc welding method for the high-strength hybrid steel cruciform joint according to claim 1, characterized in that in the step of filling the weld, the step of welding comprises the following steps: the welding current is 550-600A, the welding voltage is 33-36V, the welding speed is 35-40 cm/min, and the heat input is 27.2-37 kJ/cm.

5. The submerged arc welding method for the high-strength hybrid steel cruciform joint according to claim 1, characterized in that in the cap weld step: the welding current is 550-600A, the welding voltage is 33-36V, the welding speed is 35-40 cm/min, and the heat input is 27.2-37 kJ/cm.

6. The submerged arc welding method for the high-strength hybrid steel cross joint as claimed in claim 1, wherein before the welding step, the welding track is cleaned, and surface impurities to be welded are removed by grinding with a grinding wheel; and after the front welding seam is welded, performing back gouging treatment on the back welding layer by adopting a carbon arc air gouging machine.

7. The submerged arc welding method for the high-strength hybrid steel cruciform joint according to claim 1, wherein the vertical plate is made of a Q690 steel plate, and the horizontal plate is made of a Q550 steel plate; or the vertical plate is made of a Q550 steel plate, and the transverse plate is made of a Q690 steel plate.

8. The submerged arc welding method for the high-strength hybrid steel cruciform joint according to claim 1, wherein the bead temperature is maintained at 120 ℃ to 200 ℃ during welding.

9. The submerged arc welding method for the high-strength hybrid steel cruciform joint according to claim 1, characterized in that the welding equipment used in the welding process is an automatic submerged arc welding vehicle; the welding wire is a low-strength matching SUN2M31 type welding wire; the flux is TH-SJ 101 type flux.

Technical Field

The invention relates to the technical field of high-strength mixed steel welding, in particular to a submerged-arc welding method for a high-strength mixed steel cross joint.

Background

In recent years, with the progress of China in the field of metallurgy, low-alloy high-strength steel (steel with yield strength more than or equal to 460 MPa) obtains corresponding attention; in steel structure engineering in China, Q235 and Q355 are mainly used common steel, and high-strength steel can meet the requirements on material performance and reduce the consumption of the steel, wherein for members adopting a hybrid design concept, such as hybrid design I-shaped beams, high-strength (Q690) steel is used for flanges, and low-strength steel (Q550) is used for webs, so that the performance of the steel can be fully exerted, and the cost can be reduced.

However, the Q690 and Q550 high-strength steels have the problems of embrittlement and softening of a heat affected zone in the welding process, in the actual production, the welding of the high-strength homogeneous steels generally adopts semi-automatic gas shielded welding or automatic gas shielded welding matched with other strong welding wires, and for the high-strength mixed steels, the low-strength welding wires are matched; for the welding of high-strength mixed steel, no submerged arc welding method is researched at present in China; the welding mode of utilizing submerged arc welding based on the high-strength mixed steel can ensure stable welding quality and high production efficiency, and avoids arc light and smoke dust.

Therefore, the concept of high-strength hybrid design and the advantages of submerged-arc welding need to be combined, the submerged-arc welding process with the high-strength hybrid design is invented, the welding joint under the welding process can be guaranteed to have good mechanical properties, and the submerged-arc welding process has reference guiding significance for similar welding of other joints.

Disclosure of Invention

The invention aims to solve the defects in the prior art, and provides a submerged-arc welding method for a high-strength mixed steel cross joint.

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

a submerged-arc welding method for a high-strength hybrid steel cross joint comprises the following steps:

s1: pretreatment of welded steel: the vertical plate and the transverse plate are both made of high-strength mixed steel, and a groove is formed at one end to be welded of the transverse plate;

s2: preheating before welding: preheating the vertical plate and the transverse plate before welding, wherein the preheating temperature is not lower than 60 ℃;

s3: backing up a weld joint: bottoming the welding bead by using a low-strength matching type welding wire;

s4: filling a welding seam: filling the bottomed welding bead by using a low-strength matching type welding wire;

s5: and (4) cover surface welding seam: and adopting a low-strength matching type welding wire to cover the filled welding bead.

Furthermore, the cross plate groove cross section is the trapezium structure, and the contained angle of the first lateral wall of trapezium structure and riser is 30 ~ 60, and the contained angle of the second lateral wall of trapezium structure and riser is 30 ~ 60, and the last bottom surface width of trapezium structure is 4 ~ 5 mm.

Further, in the backing weld step: the welding current is 500-550A, the welding voltage is 30-33V, the welding speed is 35-40 cm/min, and the heat input is 22.5-31.1 kJ/cm.

Further, in the step of filling the weld: the welding current is 550-600A, the welding voltage is 33-36V, the welding speed is 35-40 cm/min, and the heat input is 27.2-37 kJ/cm.

Further, in the cap weld step: the welding current is 550-600A, the welding voltage is 33-36V, the welding speed is 35-40 cm/min, and the heat input is 27.2-37 kJ/cm.

Further, before the welding step, cleaning a welding track, polishing by adopting a grinding wheel, and removing impurities on the surface of a part to be welded; and after the front welding seam is welded, performing back gouging treatment on the back welding layer by adopting a carbon arc air gouging machine.

Further, the vertical plate is made of a Q690 steel plate, and the transverse plate is made of a Q550 steel plate; or the vertical plate is made of a Q550 steel plate, and the transverse plate is made of a Q690 steel plate.

Further, the welding bead temperature is kept between 120 ℃ and 200 ℃ during the welding process.

Furthermore, in the welding process, adopted welding equipment is an automatic submerged arc welding vehicle; the welding wire is a low-strength matching SUN2M31 type welding wire; the flux is TH-SJ 101 type flux.

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

the high-strength mixed steel is welded by a submerged arc welding method, so that the advantages of the performance of the steel are fully exerted, the welding quality is stable, and the welding efficiency is improved; and secondly, the advantages of high welding efficiency, less pollution and the like of submerged arc welding are combined, and the generation of arc light and smoke dust is avoided. The arrangement of the invention realizes the popularization and application of the submerged arc welding process of the high-strength mixed steel Q690+ Q550 on steel structure buildings.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention.

Fig. 1 is a schematic view of a welding structure in embodiment 2 of the present invention.

In the figure: 1. a transverse plate; 2. a vertical plate.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.

Example 1:

a submerged-arc welding method for a high-strength hybrid steel cross joint comprises the following steps:

s1: pretreatment of welded steel: the vertical plate and the transverse plate are both made of high-strength mixed steel, a groove is formed in one end to be welded of the transverse plate, the cross section of the groove of the transverse plate is of a trapezoidal structure, the included angle between the first side wall of the trapezoidal structure and the vertical plate is 30-60 degrees, the included angle between the second side wall of the trapezoidal structure and the vertical plate is 30-60 degrees, and the width of the upper bottom surface of the trapezoidal structure is 4-5 mm;

s2: preheating before welding: preheating the vertical plate and the transverse plate before welding, wherein the preheating temperature is not lower than 60 ℃;

s3: backing up a weld joint: and (3) bottoming the welding bead by using a low-strength matching type welding wire, wherein the welding current is 500-550A, the welding voltage is 30-33V, the welding speed is 35-40 cm/min, and the heat input is 22.5-31.1 kJ/cm.

S4: filling a welding seam: filling the bottomed weld bead by using a low-strength matching type welding wire, wherein the welding current is 550-600A, the welding voltage is 33-36V, the welding speed is 35-40 cm/min, and the heat input is 27.2-37 kJ/cm;

s5: and (4) cover surface welding seam: and (3) covering the filled welding bead by using a low-strength matching type welding wire (the specific model of the welding wire is THM-10Mn2NiMoA solid welding wire), wherein the welding current is 550-600A, the welding voltage is 33-36V, the welding speed is 35-40 cm/min, and the heat input is 27.2-37 kJ/cm. .

Before the welding step, cleaning a welding track, polishing by adopting a grinding wheel, and removing surface impurities at a position to be welded; after the front weld joint welding is finished, the back welding layer is subjected to back gouging treatment by adopting carbon arc air gouging

During the welding process (backing weld, filling weld and cover weld), the weld bead temperature is kept between 120 ℃ and 200 ℃.

Example 2:

the invention relates to a welding process of submerged arc welding aiming at a high-strength hybrid design Q690+ Q550 cross joint, which comprises the following steps of controlling materials and parameters in the welding process:

(1) welding materials: selecting a low-strength matched SUN2M31 type welding wire with the diameter of 3.2 mm; SU34 type flux;

(2) description of materials: the vertical plate 2 adopts a Q690 steel plate; the transverse plate 1 is made of a thick Q550 steel plate;

(3) groove form: according to the materials and the welding position of the flat welding, X-shaped grooves are adopted on the two sides; the front surface (theta 1) is 45-60 degrees, the back surface (theta 2) is 45-60 degrees, and the truncated edge (H) is 4-5 mm, as shown in figure 1;

(4) preheating before welding: the preheating temperature before welding is not lower than 60 ℃;

(5) inter-lane temperature: adopting multilayer multi-pass welding, and controlling the temperature between passes to be 120-200 ℃;

(6) backing up a weld joint: the welding current is 500-550A, the welding voltage is 30-33V, the welding speed is 35-40 cm/min, and the heat input is 22.5-31.1 kJ/cm;

(7) filling a welding seam: the welding current is 550-600A, the welding voltage is 33-36V, the welding speed is 35-40 cm/min, and the heat input is 27.2-37 kJ/cm;

(8) and (4) cover surface welding seam: the welding current is 550-600A, the welding voltage is 33-36V, the welding speed is 35-40 cm/min, and the heat input is 27.2-37 kJ/cm;

the cleaning mode is as follows: cleaning before welding by adopting a grinding wheel to polish and remove oxide skin, rust and oily water on the surface of a part to be welded; and back gouging adopts carbon arc gouging.

Example 3:

the Q690+ Q550 high-strength mixed steel cross joint submerged-arc welding process adopts the welding groove in the form of the figure 1, and the welding material is Tianjin bridge welding material.

Description of parent material: the vertical plate is a Q690 steel plate with the thickness of 20 mm; the transverse plates are Q550 steel plates with the thickness of 20 mm;

welding equipment: MZC-1250M automatic submerged arc welding car;

baking the flux: keeping the temperature at 350 ℃ for 2 h;

preheating temperature: 60 ℃, interchannel temperature: 120-200 ℃;

the front surface (theta 1) of the groove form is 45 degrees, the back surface (theta 2) is 60 degrees, the truncated edge (H) is 4-5 mm,

TABLE 1

By adopting the welding process in the table 1, the average tensile strength of the cross joint reaches 833.5 MPa;

the average value of the impact energy at the temperature of the heat affected zone to 20 ℃ is 266J, and the average value of the impact energy at the temperature of the weld zone to 20 ℃ is 166J;

the hardness of the cross joint is highest in the heat affected zone of the vertical plate and reaches 334.8HV10, and the performances meet the specification requirements.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.