CN103920975B - High performance structures steel Q460GJC welding technology of automatic submerged-arc welding for building - Google Patents

Abstract

The invention discloses a kind of high performance structures steel Q460GJC welding technology of automatic submerged-arc welding for building, this welding procedure 1. welding material: welding wire selects H08MnMoA, and SJ101 selected by solder flux; 2. double V groove or V-butt is selected according to thickness of slab; 3. before welding, preheat temperature is not less than 100 DEG C; 4. adopt multi-layer multi-pass welding, between road, temperature is 100 ~ 170 DEG C.Welding procedure of the present invention solves building high performance structures steel Q460GJC under the effect of Lincoln weld high heat input, the problem that weld heat-affected zone impact flexibility declines to a great extent, the high comprehensive performance of welding point, reach the tough object such as strong with mother metal etc., the successful Application of Q460GJC high-performance steel at field of steel structure can be ensured, improve the scientific and technological level of China's welding for steel structure, the development promoting China's steel construction construction is had great importance.

Description

High performance structures steel Q460GJC welding technology of automatic submerged-arc welding for building

Technical field

The present invention relates to construction steel structure welding technology field, the welding technology of automatic submerged-arc welding of high performance structures steel Q460GJC especially for building.

Background technology

In structural steelwork, adopt high performance structures steel significantly can reduce the consumption of steel, greatly reduce the energy smelting steel consumption accordingly, the final energy reducing unit construction area and consume.The annual structural steel for building of China more than 3,000 ten thousand tons, if wherein 10% adopt high performance structures steel, i.e. high performance structures steel consumption about 3,000,000 tons, after adopting high performance structures steel, steel using amount can reduce 15%, and steel construction cost per ton presses 10000 yuan of calculating, then nearly 5,000,000,000 yuan of cost of can reducing investment outlay.

Current China steel construction mainly uses the common irons such as Q235 and Q345, and the use of high performance structures steel in steel construction is also fewer, along with the development of country, the construction dynamics of the large-scale construction engineerings such as skyscraper, high-rise building, large span stadiums, airport, conference and exhibition center and steel-structure factory building strengthens day by day, and the market application demand of steel plate for tall building is increasing.Steel plate for tall building has the performance such as antidetonation, low-temperature impact resistance, and compared with ordinary carbon steel or low alloy steel plate, yield strength sets the upper limit, and tensile strength is improved, and has requirement to carbon equivalent, yield tensile ratio index.China's steel construction does not have supporting design specification to intensity more than the high-strength steel of 420MPa.

For the produce in factory weld seam of steel construction, Lincoln weld welding method has more outstanding advantage with its automatic welding mode, higher production efficiency, good welding quality and working condition, be specially adapted to the manufacture of large welded structures, the Lincoln weld therefore realizing Q460GJC steel has important practical significance.

Q460GJC carbon content of steel low (being less than 0.18%), S, P content is low, on the basis of low-carbon (LC), by adding the alloying element of raising quenching degree and obtaining the good tissue of strength high toughness by normalizing heat treatment, thus ensure the comprehensive mechanical performance that steel plate is good.Meanwhile, Q460GJC steel, compared with common Q 460 steel, adds the requirement of yield tensile ratio, and proposes satisfied requirement to Z-direction performance, and thickness effect is very little on the impact of yield strength.

Lincoln weld also considerably increases the input of weld heat input, and therefore, the welding difficulty problem of Q460GJC steel set forth above will be more outstanding.

Because Q460GJC steel possesses above characteristic, and Lincoln weld belongs to the larger welding method of heat input, the feature of its big current, high deposition rate is while enhancing productivity, also the thick and brittle of Seam and heat effected zone crystal grain can be aggravated, the phenomenon causing heat affected area impact flexibility and intensity to decline very easily occurs, and very easily produces welding cold cracking.In addition the increase to medium plate use amount in engineering actual welding, and the impact of actual welding joint complexity and constraint (restraint) degree, make that Q460GJC's be welded into a difficulties, in the urgent need to being formulated the welding procedure being applicable to Q460GJC steel by development test.

Summary of the invention

For the problems referred to above, the object of the invention is to provide a kind of building high performance structures steel Q460GJC welding procedure for more than thickness of slab 12mm pioneeringly, apply architectural to realize high performance structures steel Q460GJC.

For achieving the above object, the present invention's high performance structures steel for building Q460GJC welding technology of automatic submerged-arc welding, this welding procedure comprises the control of material and parameter in welding overall process, specific as follows:

(1) welding material: select H08MnMoA welding wire, gage of wire 4.0mm, SJ101 selected by solder flux;

(2) solder flux uses front strict drying, and bake out temperature 350 ~ 400 DEG C dries 1.5 ~ 2h;

(3) double V groove or V-butt is selected according to thickness of slab, wherein, double V groove, 60 °, front, reverse side 45 °, root face 2 ~ 3mm, root gap 0 ~ 3mm; V-butt angle is 45 ° ~ 60 °, root face 0 ~ 3mm, root gap 0 ~ 3mm;

(4) before welding, preheat temperature is 100 DEG C;

(5) adopt multi-layer multi-pass welding process, interlayer temperature is not less than described preheat temperature.

Preferably, described interlayer temperature is 100 ~ 170 DEG C.

Preferably, when carrying out submerged-arc welding downhand welding or flat fillet weld, described welding procedure also comprises:

(1) backing weld seam: welding current 520 ~ 530A, weldingvoltage 28 ~ 30V, speed of welding 38.3 ~ 41.6cm/min, heat input 21.0 ~ 24.9KJ/cm;

(2) weld seam is filled: welding current 530 ~ 550A, weldingvoltage 30 ~ 32V, speed of welding 41.6 ~ 45.0cm/min, heat input 21.2 ~ 25.4KJ/cm;

(3) cap weld: welding current 520 ~ 530A, weldingvoltage 28 ~ 30V, speed of welding 38.3 ~ 41.6cm/min, heat input 21.0 ~ 24.9KJ/cm.

Along with the raising of structural steel performance, its welding difficulty also corresponding raising.And the welding quality of weld seam is the slope type of weld seam, preheat temperature, temperature between road during multiple tracks welding, backing weld seam, fill weld seam, the welding parameter of cap weld and corresponding heat input thereof, the constraint (restraint) degree of welding point, etc. the result of many factors collaborative, comprehensive function mutually, in order to obtain qualified weld seam, with reference on existing welding conditions and empirical basis, also need to do a large amount of test and study work, to make each factor matched well.Just because of it is huge to test the workload of groping, thus hinder applying of high performance structures steel Q460GJC for building.

The present invention, as the ground-breaking research of one, when researching and developing, simply applying mechanically routine techniques parameter and cannot realize goal of the invention, and the joint after namely after welding cannot reach the performance requirement of high performance structures steel Q460GJC national standard defined for building.

Welding procedure of the present invention, solve a welding difficult problem for the Lincoln weld of high performance structures steel Q460GJC for building, weld according to this technique, the welding point comprehensive mechanical property of acquisition is excellent, the tensile strength of joint is reached with mother metal etc. strong.

The high performance structures steel Q460GJC welding procedure for building that the present invention proposes, has and instructs standardization role, filled up Q460GJC steel in China's structural steelwork and utilized Lincoln weld to carry out the blank of welding, significant for the application promoting this steel grade.

In the present invention, selecting of welding material such as to take at the tough principle such as strong, is comparatively selected by the mechanical property numeric ratio of wlding deposited metal mechanical property numerical value and steel.

The Selection experiment of groove and root gap is determined, under the prerequisite ensureing joint combination property, is controlled by welding capacity in rational scope, achieves the optimization of welding quality and efficiency.

Steel plate preheat temperature adopts double V-groove weld cracking expreiment to determine, in table 1.Consider complexity and the constraint (restraint) degree size of engineering structure, the temperature should recommended in strict accordance with the present invention carries out preheating to steel plate, and the preheat temperature lower than the present invention's recommendation can increase the possibility of weld cracking.

Table 1V type groove Q460GJC weld cracking expreiment welding parameter and result

Between minimum road, temperature should be not less than preheat temperature, otherwise very easily cracks in welding process; Between Gao road, humid test is determined, between road, the too high meeting of temperature causes heat affected area coarse grains, and weld strength and low-temperature impact toughness are declined.

The selection of welding parameter is determined according to HAZ maximum hardness test and welding procedure qualification test.According to test, the hot input range exceeding the present invention's recommendation welds, can due to the excessive and too small welding quality affecting steel plate of heat input.Heat input is excessive, and alloying element scaling loss is serious, and weld heat-affected zone is organized thick, and strength of joint, toughness reduce, in table 2, heat input is simultaneously too high be also produce burn, the major reason of the defect such as undercut or solidification cracking; Heat input is too small, and electric arc is unstable, easily causes lack of penetration and generation that is incomplete fusion defect.

Table 2 adopts high heat-input (note 1) welding parameter connector test result

Note:

1 adopts thermal weld stress scope 28.6 ~ 34KJ/cm, exceedes more than 13% of recommended upper limit of the present invention;

2Q460GJC steel plate tensile strength standard value 550 ~ 720MPa, impact absorbing energy >=34J.

Accompanying drawing explanation

Fig. 1 is the schematic diagram of X-type groove type in welding procedure of the present invention;

Fig. 2 is the schematic diagram of V-type cut form in welding procedure of the present invention.

Detailed description of the invention

Below in conjunction with Figure of description, the present invention will be further described.

Building high performance structures steel Q460GJC submerged-arc welding (downhand welding) welding procedure, bevel for welding adopts the double V groove form shown in Fig. 1, and wlding selects Atlantic Ocean wlding.

Welding equipment: CD-1250B

Preheat temperature: 100 DEG C, layer temperature: 100 ~ 170 DEG C, sheet metal thickness 48mm, other parameters see the following form.

The wlding result of the test adopting above welding procedure to carry out sees the following form, and qualification of welding procedure is qualified.

In addition, if when sheet metal thickness is less than 25mm, also the double V-groove shown in Fig. 2 can be adopted.

Above; be only better enforcement example of the present invention, but protection scope of the present invention is not limited thereto, is anyly familiar with those skilled in the art in the technical scope that the present invention discloses; the change that can expect easily or replacement, all should be encompassed within protection scope of the present invention.

Claims (1)

1. high performance structures steel Q460GJC submerged-arc welding automatic soldering technique for building, the thickness of slab of structural steel Q460GJC is not less than 12mm, and its technique is specific as follows:

(1) welding material: select H08MnMoA welding wire, gage of wire 4.0mm, SJ101 selected by solder flux;

(2) solder flux strictly cures before using, and stoving temperature 350 ~ 400 DEG C, cures time 1.5 ~ 2h;

(3) double V groove or V-butt is selected according to thickness of slab, wherein, double V groove, 60 °, front, reverse side 45 °, root face 2 ~ 3mm, root gap 0 ~ 3mm; V-butt angle is 45 ° ~ 60 °, root face 0 ~ 3mm, root gap 0 ~ 3mm;

(4) before welding, preheat temperature is 100 DEG C;

(5) adopt multi-layer multi-pass welding process, between road, temperature is 100 ~ 170 DEG C, and between road, temperature is not less than described preheat temperature;

When carrying out downhand welding or the welding of flat fillet weld position, described welding procedure also comprises:

(1) backing weld seam: welding current 520 ~ 530A, weldingvoltage 28 ~ 30V, speed of welding 38.3 ~ 41.6cm/min, heat input 21.0 ~ 24.9KJ/cm;

(2) weld seam is filled: welding current 530 ~ 550A, weldingvoltage 30 ~ 32V, speed of welding 41.6 ~ 45.0cm/min, heat input 21.2 ~ 25.4KJ/cm;

(3) cap weld: welding current 520 ~ 530A, weldingvoltage 28 ~ 30V, speed of welding 38.3 ~ 41.6cm/min, heat input 21.0 ~ 24.9KJ/cm.