CN116727814A - Welding process for bridge steel Q370qE ultra-thick plate - Google Patents

Abstract

The invention relates to a welding process of a bridge steel Q370qE ultra-thick plate, which is used for butt joint of Q370qE steel with the plate thickness of 150 mm; the method is characterized in that: the specific welding process is as follows: the method comprises the steps of groove form, general requirements including pre-welding polishing, arc striking and extinguishing plate installation, pre-welding preheating, positioning welding, formal welding seam welding, post-welding heat preservation, nondestructive detection and the like; the positioning welding adopts J507Q welding rod upward welding and is opposite to the priming weld bead; the priming weld bead is welded by adopting a solid welding wire ER50-6, the preheating temperature is 80-120 ℃, the welding current is 220-260A, and the arc voltage is 26-30V; the multi-layer multi-pass welding of the filling layer adopts submerged arc welding wire H08Mn2E and SJ101q flux for welding, the interlayer temperature is controlled at 80-200 ℃, the welding current is 600-700A, the arc voltage is 28-32V, and the welding speed is 20-26m/H; the invention performs various welding tests and mechanical property tests, determines welding steps and welding process parameters, and ensures the quality of welding seams.

Description

A kind of bridge steel Q370qE ultra-thick plate welding process

Technical field

The invention relates to the technical field of bridge construction, and in particular to a welding process of bridge steel Q370qE ultra-thick plates.

Background technique

At present, the thickest bridge steel plate used in China is 120mm, and the Q370qE bridge steel plate with a plate thickness of 150mm is used for the first time; this process takes into account the groove form, preheating temperature, positioning welding, welding method, deformation control and other measures to carry out various Welding test, mechanical test, determine welding steps and welding process parameters.

Contents of the invention

The technical problem to be solved by this invention is to provide a bridge steel Q370qE ultra-thick plate welding process that can solve the welding problem of 150mm Q370qE steel plate.

In order to solve the above technical problems, the technical solution of the present invention is: a bridge steel Q370qE ultra-thick plate welding process, which is used for butt jointing of Q370qE steel with a plate thickness of 150mm; its innovation point is: the specific welding process is as follows:

Use a milling machine to process the groove of 150mm Q370qE steel. Clean the groove before welding and preheat it to 120-150℃;

The 150mm Q370qE steel positioning welding and bottoming welding beads are set on opposite sides;

150mm Q370qE steel overhead welding uses electrode arc welding;

The formal weld of 150mm Q370qE steel adopts a combination of gas shielded welding and submerged arc welding;

150mm Q370qE steel is subjected to post-heat treatment after welding. Both sides of the weld are heated to 200-250°C. After post-heating, asbestos is spread on the weld for thermal insulation and slow cooling. Ultrasonic flaw detection is performed 48 hours after the welding is completed.

Furthermore, the butt weld adopts a double-sided U-shaped groove with a groove angle of 30 degrees, a blunt edge of 3mm, and a radius of the root arc segment of 7mm.

Furthermore, before preheating, polish away the rust, oil stains, and pre-coated primer within 20-30mm on both sides of the weld to reveal the metallic luster.

Furthermore, the preheating adopts electric heating, and the heating range is 100mm on both sides of the weld and 100mm on the symmetrical side of the weld to ensure stress balance and prevent tack welding from cracking.

Further, tack welding is performed on the back side of the base weld bead, using J507Q electrode welding to eliminate the impact of tack welding on the base weld bead. Carbon arc gouging is performed before welding on the tack weld side to remove the tack weld seam and unfused area.

Furthermore, solid wire ER50-6 is used for flat position welding for the bottom welding pass, and the thickness of the welding seam is controlled at 3-4mm; the welding current is 220-260A, and the arc voltage is 26-30V.

Furthermore, multi-layer and multi-pass welding is used to fill the weld. The welding material is submerged arc welding wire H08Mn2E plus submerged arc flux SJ101q. After welding three layers, turn it over and perform carbon arc gouging to remove the unfused area. After polishing it evenly, submerged arc is used. Automatic welding, both sides of the weld are alternately welded, turning over every four layers of welding, ensuring continuous welding, and the arc should not be interrupted; the thickness of the weld is controlled at 4-5mm, and the inter-layer temperature is controlled at 80-200°C. The current is 600-700A, the arc voltage is 28-32V, and the welding speed is 20-26m/h.

The advantages of the present invention are:

1) In the present invention, the positioning welding uses J507Q electrode in the upward position, on the opposite side from the bottom welding bead; the bottom welding bead is welded with solid wire ER50-6, the preheating temperature is 80-120°C, the welding current is 220~260A, and the arc The voltage is 26-30V; the filling layer is multi-layer and multi-pass welding, using submerged arc welding wire H08Mn2E and SJ101q flux welding, the interlayer temperature is controlled at 80-200°C, the welding current is 600-700A, the arc voltage is 28-32V, the welding speed is 20-26m/h; the present invention conducts various welding tests and mechanical performance tests to determine the welding steps and welding process parameters to ensure the quality of the weld.

Description of drawings

The present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

Figure 1 is a diagram of the plate butt groove form of the bridge steel Q370qE ultra-thick plate welding process of the present invention.

Figure 2 is a schematic diagram of the pre-welding preheating process of the bridge steel Q370qE ultra-thick plate welding process of the present invention.

Figure 3 is a schematic diagram of the positioning welding process of the bridge steel Q370qE ultra-thick plate welding process of the present invention.

Figure 4 is a welding seam layout diagram of the plate butt jointing process of the bridge steel Q370qE ultra-thick plate welding process of the present invention.

Implementation

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, rather than all embodiments. The components of the embodiments of the invention generally described and illustrated in the figures herein may be arranged and designed in a variety of different configurations.

Therefore, the following detailed description of the embodiments of the invention provided in the appended drawings is not intended to limit the scope of the claimed invention, but rather to represent selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present invention.

As shown in Figures 1 to 4, a bridge steel Q370qE ultra-thick plate welding process is used for the butt jointing of Q370qE steel with a plate thickness of 150mm; the specific welding process is as follows:

The groove of 150mm Q370qE steel is processed with a milling machine. The butt weld adopts a double-sided U-shaped groove with a groove angle of 30 degrees, a blunt edge of 3mm, and a radius of the root arc segment of 7mm. Before preheating, 20 - Rust, oil stains, and pre-coated primer within a 30mm range are polished to expose the metallic luster; preheating uses electric heating, and the heating range is 100mm on both sides of the weld and 100mm on the symmetrical side of the weld to ensure stress balance and prevent positioning Weld cracking; and preheat to 120-150℃.

The 150mm Q370qE steel tack welding and the primer bead are set on opposite sides; tack welding is performed on the back of the primer bead, and J507Q electrode is used for welding to eliminate the impact of tack welding on the primer bead. Carbon arc gas is used before welding on the tack weld side. Plane and remove the positioning weld and unfused area; use solid wire ER50-6 for flat position welding for the bottom weld, and weld one bottom bead with the weld thickness controlled at 3-4mm; the welding current is 220-260A, and the arc voltage is 220-260A. is 26-30V.

150mm Q370qE steel overhead welding uses electrode arc welding;

The formal weld of the 150mm Q370qE steel uses a combination of gas shielded welding and submerged arc welding; the filling weld uses multi-layer multi-pass welding, and the welding material is submerged arc welding wire H08Mn2E plus submerged arc flux SJ101q. After welding three layers, turn over and proceed. Carbon arc gouging is used to remove unfused areas, and then submerged arc automatic welding is used after smooth polishing. Welding seams are alternately welded on both sides and turned over every four layers. During welding, continuous welding is ensured and the arc should not be interrupted; weld seam thickness Control it at 4-5mm, the interlayer temperature at 80-200℃, the welding current at 600-700A, the arc voltage at 28-32V, and the welding speed at 20-26m/h.

150mm Q370qE steel is subjected to post-heat treatment after welding. Both sides of the weld are heated to 200-250°C. After post-heating, asbestos is spread on the weld for thermal insulation and slow cooling. Ultrasonic flaw detection is performed 48 hours after the welding is completed.

Those skilled in the industry should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will also have other aspects. Various changes and modifications are possible, which fall within the scope of the claimed invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims (7)

1. A bridge steel Q370qE ultra-thick plate welding process, which is used for butt jointing Q370qE steel with a plate thickness of 150mm; it is characterized by: the specific welding process is as follows: Use a milling machine to process the groove of 150mm Q370qE steel. Clean the groove before welding and preheat it to 120-150℃; The 150mm Q370qE steel positioning welding and bottoming welding beads are set on opposite sides; 150mm Q370qE steel overhead welding uses electrode arc welding; The formal weld of 150mm Q370qE steel adopts a combination of gas shielded welding and submerged arc welding; 150mm Q370qE steel is subjected to post-heat treatment after welding. Both sides of the weld are heated to 200-250°C. After post-heating, asbestos is spread on the weld for thermal insulation and slow cooling. Ultrasonic flaw detection is performed 48 hours after the welding is completed. 2. A bridge steel Q370qE ultra-thick plate welding process according to claim 1, characterized in that: the butt weld adopts a double-sided U-shaped groove with a groove angle of 30 degrees, a blunt edge of 3mm, and a root arc. Segment radius 7mm. 3. A bridge steel Q370qE ultra-thick plate welding process according to claim 1, characterized in that: before preheating, the rust, oil stains and pre-coated primer within the range of 20-30mm on both sides of the weld are polished and exposed. Metallic luster. 4. A bridge steel Q370qE ultra-thick plate welding process according to claim 1, characterized in that: the preheating adopts electric heating, and the heating range is 100mm on both sides of the weld and 100mm on the symmetrical side of the weld. Ensure stress balance and prevent tack welding from cracking. 5. A bridge steel Q370qE ultra-thick plate welding process according to claim 1, characterized in that: positioning welding is performed on the back of the base weld bead, and J507Q electrode is used for welding to eliminate the influence of positioning welding on the base weld bead. Carbon arc gouging is performed before welding on the tack welding side to remove the tack weld seam and unfused area. 6. A bridge steel Q370qE ultra-thick plate welding process according to claim 1, characterized in that: the bottom weld bead is welded flat with solid wire ER50-6, and the bottom weld bead is welded together, and the thickness of the weld is controlled within 3-4mm; welding current is 220-260A, arc voltage is 26-30V. 7. A bridge steel Q370qE ultra-thick plate welding process according to claim 1, characterized in that: the filling weld adopts multi-layer multi-pass welding, the welding material is submerged arc welding wire H08Mn2E plus submerged arc flux SJ101q, and welding three layers Then turn over, perform carbon arc gouging, remove the unfused area, polish it evenly and then use submerged arc automatic welding. Alternately weld both sides of the weld. Turn over once every four welding layers. Ensure continuous welding during welding, and the arc should not be interrupted. ;The weld thickness is controlled at 4-5mm, the interlayer temperature is controlled at 80-200℃, the welding current is 600-700A, the arc voltage is 28-32V, and the welding speed is 20-26m/h.