CN104942104B

CN104942104B - Thermal roll-forming process of unequal-thickness U-ribs

Info

Publication number: CN104942104B
Application number: CN201510224954.5A
Authority: CN
Inventors: 韩静涛; 彭雪锋; 葛云杰; 陈强
Original assignee: University of Science and Technology Beijing USTB
Current assignee: University of Science and Technology Beijing USTB
Priority date: 2015-05-05
Filing date: 2015-05-05
Publication date: 2017-02-22
Anticipated expiration: 2035-05-05
Also published as: CN104942104A

Abstract

The invention belongs to the technical field of thermal roll-forming and relates to a thermal roll-forming process of unequal-thickness U-ribs. The process includes the steps of 1, feeding a pre-formed U-rib formed by the traditional cold-bending process into an induction heater through a feed rack, selecting a proper heating area through an adjusting mechanism, and feeding the pre-formed U-rib into a roll-forming unit after a temperature required temperature is reached; 2, acquiring a formed U-rib in unequal thickness, formed by the roll-forming unit having two passes, for rough forming and finish forming, respectively, with great residual stress in corners and ends caused by cold bending and thermal roll-forming deformation; 3, feeding the formed U-rib into a continuous destressing annealer which is used mainly for destressing and annealing the bent parts and ends of the U-rib in the unequal thickness, with higher thermal efficiency; and 4, allowing cooling and performing cutting to length. The process has the advantages that forming speed is high, thermal efficiency is high, the formed U-rib has low residual stress, welding area of the U-rib and a bridge deck is enlarged, and connection strength of the U-rib and the bridge deck and fatigue resistance of a weld are improved.

Description

A kind of non-uniform thickness U rib hot-rolling pressing formation technique

Technical field

The present invention relates to a kind of bridge U rib forming technique, the localized heat of the non-uniform thickness U rib in particularly a kind of end is rolled into Type technology.

Background technology

At present in field of bridge construction, cross bridge floor board is widely used in science of bridge building, orthogonal different Mainly by steel bridge deck and the crossbeam welding, longitudinal rib are constituted with it, crossbeam is mainly diaphragm plate to property floorings, and longitudinal rib is mainly Ribbed stiffener of remaining silent is U rib.Because U-shaped rib can provide larger torsional rigidity and bending rigidity, whole floorings can be improved Stress, therefore become the most frequently used section form of modern cross bridge floor board.

But recent domestic continuously emerges the report with regard to above-mentioned U-shaped rib fatigue harm, causes the fatigue of floorings Life-span is less than the design life that bridge main body requires.Experience have shown that, produce this fatigue crack the reason be：Due to U-shaped Rib is closed configuration, can only be from outside one side welding in welding, commonly used 75～85% partial penetration weldering, bonding area Less；And stay 15～25% incomplete fusion part, the incomplete fusion part of about 2～3mm, this 2～3mm is formed for one in itself Natural initial crack, becomes fatigue crack source, under alternate load effect, leads to floorings easily tired with U rib commissure Cracking.Fatigue crack is once produce the rigidity that will reduce floorings, and then reduces the life-span of whole bridge.

For solve disadvantages described above, patent documentation CN201310313688.4, CN201420305499.2 and CN201420544235.2 successively proposes to adopt the U-shaped ribbed stiffener of non-uniform thickness, and that is, U rib and floorings connecting portion are thickeied, with Increase the bonding area of U rib and floorings, improve the anti-fatigue performance of weld seam, but above-mentioned patent documentation does not provide enforcement Method, though the method that patent documentation CN201420274989.0 proposes non-uniform thickness U rib, is using hot rolling forming technology, This process materials utilization rate and the thermal efficiency are relatively low, and U rib length has been limited.

Content of the invention

Bonding area for solving the problems, such as existing U rib and floorings is little, the easy fatigue cracking of weld seam, and the present invention proposes A kind of end non-uniform thickness U rib hot-rolling pressing formation technique.

The technical scheme is that：1) with the preforming U rib of traditional cold bending process shaping as raw material, it is by rotary shafts Send into induction heating apparatus, suitable heating region is selected by guiding mechanism, after reaching target call heating-up temperature, send into roller Pressing formation device；2) forming device is made up of two passages, and its effect is dumming respectively and essence shapes, and the end after shaping is non- Uniform thickness U rib, because clod wash and hot-rolling compressive strain all have larger residual stress in corner and end；3) subsequently enter and continuously go Stress annealing stove, this annealing furnace, mainly for the crooked position of U rib and end stress relief annealing, improves the thermal efficiency；4) after, cold But, cutting to length.

In the present invention, described preforming U rib thickness scope is 6～12mm.

In the present invention, described induction heating apparatus is intermediate frequency, induction coil width of heating and depth bounds be 6 respectively～ 20mm and 20～70mm.Its guiding mechanism is made up of worm and gear, achievable induction coil up and down, move left and right, adjust distance It is all 200mm.

In the present invention, described forming device is made up of two passages, and respectively dumming and essence shape.

In the present invention, described forming temperature is interval to be 850～1050 DEG C.

In the present invention, described continuous stress relief annealing stove, use resistance furnace, major heated zones domain in corner and End, is local destressing annealing.

The present invention compared with prior art, is had advantageous effect in that：

1) present invention firstly provides a kind of non-uniform thickness U rib hot-rolling pressing formation technique, soon, the thermal efficiency is high, obtains for its forming speed The U rib residual stress arriving is little, and increases the bonding area with floorings, improves bonding strength and the weldering of U rib and floorings The anti-fatigue performance of seam；

2) induction heating apparatus of the present invention, wide accommodation, the U rib of different-thickness and heat penetration can be met, And the hot-rolling pressing formation of different size U rib is can achieve by guiding mechanism；

3) present invention can be convenient and swift as a Module-embedding in traditional clod wash production technology, can meet difference The cutting to length of length；

4) continuous stress relief annealing stove of the present invention, uses resistance furnace, major heated zones domain in corner and End, is local destressing annealing, and the thermal efficiency is high.

Brief description

Fig. 1 is a kind of non-uniform thickness U rib hot-rolling pressing formation process structure schematic diagram of present invention design.

Fig. 2 is the induction heating apparatus schematic diagram of present invention design.

Fig. 3 is the rolling formation schematic device of present invention design.

Fig. 4 is the continuous stress relief annealing furnace apparatus schematic diagram of present invention design.

Fig. 5 A is the bonding area schematic diagram of common U rib and floorings.

Fig. 5 B is the partial enlarged drawing of Fig. 5 A.

Fig. 6 A is the bonding area schematic diagram of non-uniform thickness U rib and floorings.

Fig. 6 B is the partial enlarged drawing of Fig. 6 A.

It is numbered shown in figure：1 preforming U rib, 2 induction heating apparatuses, about 21 guiding mechanisms, 22 about adjustment machines Structure, 3 induction coils, 4 bottom rollers, 5 regulating bolts, 6 fixed mounts, 7 rolls, 71 pressure rollers, 72 bulging rollers, 8 stress relief annealing stoves, 81 Furnace shell, 82 resistance wires, 9 non-uniform thickness U ribs

Specific embodiment

The present invention is described in detail with specific embodiment below in conjunction with the accompanying drawings：

Take the preforming U rib 1 that traditional cold bending process shapes to be raw material, send into induction heating apparatus 2 by rotary shafts, pass through Guiding mechanism 21 and left and right adjusting mechanism 22 select suitable heating region up and down, after reaching the heating-up temperature of target call, send Enter rolling formation device, set by regulating bolt 5 pressure roller 71 drafts size, shaping groove by depress roller 71 and support Pressure roller 72 forms, and subsequently enters continuous stress relief annealing stove 8, has disposed resistance wire 82 in stress relief annealing furnace shell 81 corner, main To be directed to crooked position and the end annealing of U rib, obtain non-uniform thickness U rib 9 sample, afterwards cooling, cutting to length.

Embodiment 1

Choose Q345d plate, thickness 8mm, pre-bending is carried out by traditional cold bending technique, heating is adjusted by guiding mechanism Region is 35mm, sets heating-up temperature as 900 DEG C, feed speed 9m/min and drafts as 5mm, after hot-rolling pressing formation, connects Stress relief annealing.After testing, the non-uniform thickness U rib residual stress obtaining is little, and is common U rib weldering with the bonding area of floorings Amass 2.7 times of junction, substantially increase U rib and the bonding strength of floorings and the anti-fatigue performance of weld seam.

Claims

1. a kind of non-uniform thickness U rib hot-rolling pressing formation technique it is characterised in that：1) the preforming U rib being shaped with traditional cold bending process For raw material, it sends into induction heating apparatus by rotary shafts, selects suitable heating region by guiding mechanism, and reaching target will After seeking heating-up temperature, send into rolling formation device；2) forming device is made up of two passages, and its effect is dumming and essence respectively Shape, the non-uniform thickness U rib of the end after shaping, because clod wash and hot-rolling compressive strain all exist relatively in the crooked position of U rib and end Big residual stress；3) subsequently enter continuous stress relief annealing stove, continuous stress relief annealing stove is mainly for the crooked position of U rib With end stress relief annealing, improve the thermal efficiency；4) after, cooling, cutting to length；Described preforming U rib thickness be 6～ 12mm；

Described induction heating apparatus is intermediate frequency, and width of heating and depth bounds are 6～20mm and 20～70mm respectively；Shape temperature Degree is interval to be 850～1050 DEG C.

2. a kind of non-uniform thickness U rib hot-rolling pressing formation process according to claim 1 it is characterised in that：Described company Continuous stress relief annealing stove, uses resistance furnace, and major heated zones domain, in the crooked position of U rib and end, is local destressing Annealing.