CN104353668A - Production line for rolling hollow steel and rolling forming production method for hollow steel - Google Patents

Abstract

The invention discloses a production line for rolling hollow steel and a rolling forming production method for hollow steel. The production line comprises a heating furnace, a roughing rolling unit, an intermediate rolling unit, a precision rolling unit and a cold bed which are arranged in sequence in the rolling direction, wherein the roughing rolling unit, the intermediate rolling unit, and the precision rolling unit are respectively formed by a plurality of four-roller rolling machines arranged in a staggered manner; the four-roller rolling machines can form circular or hexagonal rolling holes; the included angle between every two adjacent rolling machines is 45 to 90 degrees; the forming method comprises the steps of heating, continuous rolling, cutting for scaling-off and cooling. According to the invention, the conventional composite rolling production line and production process for hollow steel are improved in the light of the deformation rule of metal, so that a set of multi-roll rolling (circular and hexagonal) hollow steel production line and production method is formed, the problem of easy occurrence of out-of-tolerance fracture surface dimensional precision, especially the problem of high out-of-roundness of core holes in the conventional method is eliminated from the pass-by-pass evolution theory of a rolled piece.

Description

For production line and the roll forming production method thereof of rolling cored steel

Technical field

The invention belongs to steel rolling field, relate to a kind of production line for rolling cored steel and roll forming production method thereof.

Background technology

Round-meshed shaped steel is passed through at cored steel and center, also known as W Hollow Rock Drill (being called for short rock-drill steel or steel).Its section configuration is generally circle, regular hexagon etc., and Circularhole diameter is about 5 ~ 16mm, is mainly used in the drill steel making driling explosion engineering.

Mostly existing cored steel rolling is, by carrying out composite rolling after two kinds of different materials heating simultaneously, to be separated and to draw cored steel finished product after synchronous cooling.Rolling manufacturing procedure comprises: billet scaling sawing-steel billet boring-steel billet cored-heating-rolling-cooling-scale sawing-loose core-align-collect warehouse-in.

But when carrying out the ply rolling of cored steel composite by traditional two roll pass rolling mode, because bi-material attribute is different, in deformation process, law of metal flow is also not quite similar, after the premenstrual a time oval groove of external hollow Steel material again when last groove is rolled into circle, core material is but because the difference of material properties, comparatively complete circle cannot be obtained, the cored steel interstitial hole after loosing core is caused not to be circular like this, product size precision is low, cannot design standard be reached, can not instructions for use be met; In addition, because pass adjustment difficulty is large, production management cost is caused to remain high all the time; And the production stability of the method is also poor, lumber recovery is low, and production efficiency is low, and the competitiveness of enterprise cannot be got a promotion; Though each manufacturing enterprise is repeatedly optimized adjustment to existing two roll pass rolling mode, fundamentally solve the problem not yet, the target that efficient stable is produced fails to realize.

Summary of the invention

In view of this, the object of the present invention is to provide production line and the roll forming production method thereof of a kind of production stability is high, dimensional accuracy good, core bore circularity is high cored steel.

For achieving the above object, the invention provides following technical scheme: a kind of production line for rolling cored steel, comprise the heating furnace, roughing mills, intermediate mill, mm finishing mill unit and the cold bed that set gradually along rolling direction, the four-high mill that described roughing mills, intermediate mill and mm finishing mill unit are alternately arranged by some framves respectively forms, the rolling groove that described four-high mill forms is circular or hexagon, and the roll axis angle of adjacent two rolling mills is 45 ° ~ 90 °.

Further, the two-roller mill that described roughing mills is alternately arranged by some framves forms, and the rolling groove of adjacent two rolling mills is followed successively by oval and circular, or prismatic and square, and the roll axis angle on two rolling mills is 90 °.

Further, the two-roller mill that described intermediate mill is alternately arranged by some framves forms, and the rolling groove of adjacent two rolling mills is followed successively by oval and circular, or prismatic and square, and the roll axis angle on two rolling mills is 90 °.

Further, the port of export of described roughing mills, intermediate mill and mm finishing mill unit is also provided with shearing equipment.

The present invention also proposes a kind of cored steel method for rolling and molding for above-mentioned production line, it is characterized in that mainly comprising the following steps:

(1) continuous casting billet inserts plug after boring process, enters in heating furnace subsequently and heats;

(2) continuous casting billet is come out of the stove after being heated to tapping temperature, after high-pressure water descaling, enter continuous rolling in roughing mills, intermediate mill and mm finishing mill unit successively go out finished product section, wherein, tapping temperature≤1200 DEG C, mill speed≤the 18m/s of continuous casting billet in mm finishing mill unit, in four-high mill, the lengthening coefficient of one-pass roller controls between 1.15-1.4, and in two-roller mill, the lengthening coefficient of one-pass roller controls between 1.1-1.25;

(3) roll out the cored steel after finished product section and cut scale or multiple length through shearing equipment, then enter cold bed cooling;

(4) finishing process.

Beneficial effect of the present invention is:

(1) the present invention improves composite rolling production line and the technique of traditional cored steel from metal plastic flow, define production line and the process of a set of multiroll rolling (circular, hexagon) cored steel, the compression while that the pass be made up of four rollers carrying out multidirectional to hollow steel rod elements and plug, distortion and the cold draw Multidirectional synchronous of rod member and plug carry out, and what develop from rolled piece by passage eliminates the problem that the cross dimensions precision easily produced existing production method is overproof, metal spreads inequality, especially core bore out-of-roundness is high in theory.

(2) the present invention further improves rolled piece surface quality and rolling internal stress by multiple roll Multidirectional synchronous compress mode, external hollow steel rod elements and core shape are better controlled, improve product quality and rolled piece precision, finally meet product instructions for use, achieve mass steady production, also reduce production cost, improve production efficiency and lumber recovery, improve enterprise competitiveness.

Accompanying drawing explanation

In order to make object of the present invention, technical scheme and beneficial effect clearly, the invention provides following accompanying drawing and being described:

Fig. 1 is production line schematic diagram;

Fig. 2 is four rolling flow charts;

Fig. 3 is two roller-tetra-roller combined type rolling flow charts.

Detailed description of the invention

Below in conjunction with accompanying drawing, the preferred embodiments of the present invention are described in detail.

As shown in the figure, production line for rolling cored steel of the present invention, comprise the heating furnace 1, roughing mills 2, intermediate mill 3, mm finishing mill unit 4 and the cold bed 5 that set gradually along rolling direction, the four-high mill that described roughing mills 2, intermediate mill 3 and mm finishing mill unit 4 are alternately arranged by some framves respectively forms, the rolling groove that described four-high mill forms is circular or hexagon, and the roll axis angle of adjacent two rolling mills is 45 ° ~ 90 °.

In the present embodiment, roughing mills 2, intermediate mill 3 and mm finishing mill unit 4 form Continuous mill train, comprise 6 frame four-roll universal rolling machines in each unit; During rolling hollow round steel, four rolls are divided equally and are arranged and form circular port, and the angle between adjacent two roll axis is 90 °, and the roll on adjacent two rolling mills is with 45 ° of deflection angle interlaced arrangement; During rolling hollow hexagonal steel, four rolls are arranged symmetrically with and form hex hole, a pair roller occupies 120 ° of angles, another breaker roll occupies 60 ° of angles, roll on adjacent two rolling mills is with 60 ° of deflection angle interlaced arrangement, and this arrangement is convenient to roll and is nipped distortion, and is easy to control the section configuration in continuous modification process, prevent rolled piece at opening roll gap place because continuous deformation rolling forms " ears or side handles of a utensil ", and then form defects such as " folding " in the follow-up operation of rolling; The compression while that the present embodiment carrying out multidirectional by the pass be made up of four rollers to hollow steel rod elements and plug, makes the distortion of rod member and plug and cold draw Multidirectional synchronous carry out, and when eliminating two roller bi-directional compression, metal spreads uneven present situation.

As the further improvement of such scheme, described roughing mills 2 and intermediate mill 3 can select two roller Continuous mill train according to the setting of the operation of rolling, the combined type Continuous mill train of " two roller-two roller-tetra-rollers " or " two roller-tetra-roller-tetra-rollers " is formed with mm finishing mill unit 4, the two-roller mill that wherein two roller Continuous mill train are alternately arranged by some framves forms, the rolling groove of adjacent two rolling mills is followed successively by oval and circular, or prismatic and square, and the roll axis angle on two rolling mills is 90 °.

As the further improvement of such scheme, described roughing mills 2, intermediate mill 3 are also provided with shearing equipment 6 with the port of export of mm finishing mill unit 4, for excising rolled piece irregular limit shape head, are beneficial to the rolling of lower passage rolled piece.

The present invention also proposes a kind of cored steel method for rolling and molding for above-mentioned production line, it is characterized in that mainly comprising the following steps:

(1) continuous casting billet inserts plug after boring process, enters in heating furnace subsequently and heats;

(2) continuous casting billet is come out of the stove after being heated to tapping temperature, after high-pressure water descaling, enter continuous rolling in roughing mills, intermediate mill and mm finishing mill unit successively go out finished product section, wherein, tapping temperature≤1200 DEG C, mill speed≤the 18m/s of continuous casting billet in mm finishing mill unit, in four-high mill, the lengthening coefficient of one-pass roller controls between 1.15-1.4, and in two-roller mill, the lengthening coefficient of one-pass roller controls between 1.1-1.25, and shaping passage is not less than 4 times;

For improving the rolling precision of rolling unit, rolling unit selects circle or the hexagonal hole shape tandem mill of four roller compositions, raw material adopts circular cross section blank, hole on blank is filled by the plug of correspondingly-sized, guarantees that the pass of four roller compositions carries out Multidirectional synchronous compression to circular or hexangle type cored steel; The visual adjustment of different situations correspondence rolling mill practice, rolling pass and lengthening coefficient.What this technique adopted is circular cross section gradual manner, and the section configuration of the outside rod member of sustainable guarantee cored steel and plug, maintains circular cross section all the time, improve cross dimensions precision, eliminate out-of-roundness.

(3) roll out the cored steel after finished product section and cut scale or multiple length through shearing equipment, then enter cold bed cooling;

(4) off-line is separated plug, obtains final cored steel finished product carrying out finishing process.

This technique also can adopt square cross-section blank to produce circular, hexagon cored steel product, but except rolling pass is slightly different from above-mentioned above, but for ensureing higher finished size precision (rod member and core bore), must guarantee that finished product adopts multiple roll combined pass rolling mode more than 4 in passage.

What finally illustrate is, above preferred embodiment is only in order to illustrate technical scheme of the present invention and unrestricted, although by above preferred embodiment to invention has been detailed description, but those skilled in the art are to be understood that, various change can be made to it in the form and details, and not depart from claims of the present invention limited range.

Claims (5)

1. the production line for rolling cored steel, comprise the heating furnace, roughing mills, intermediate mill, mm finishing mill unit and the cold bed that set gradually along rolling direction, it is characterized in that: the four-high mill that described roughing mills, intermediate mill and mm finishing mill unit are alternately arranged by some framves respectively forms, the rolling groove that described four-high mill forms is circular or hexagon, and the roll axis angle of adjacent two rolling mills is 45 ° ~ 90 °.

2. the production line for rolling cored steel according to claim 1, it is characterized in that: the two-roller mill that described roughing mills is alternately arranged by some framves forms, the rolling groove of adjacent two rolling mills is followed successively by oval and circular, or prismatic and square, and the roll axis angle on two rolling mills is 90 °.

3. the production line for rolling cored steel according to claim 2, it is characterized in that: the two-roller mill that described intermediate mill is alternately arranged by some framves forms, the rolling groove of adjacent two rolling mills is followed successively by oval and circular, or prismatic and square, and the roll axis angle on two rolling mills is 90 °.

4. the production line for rolling cored steel according to any one of claim 1-3, is characterized in that: the port of export of described roughing mills, intermediate mill and mm finishing mill unit is also provided with shearing equipment.

5. be applicable to a cored steel method for rolling and molding for production line described in any one of claim 1-4, it is characterized in that mainly comprising the following steps:

(1) continuous casting billet inserts plug after boring process, enters in heating furnace subsequently and heats;

(2) continuous casting billet is come out of the stove after being heated to tapping temperature, after high-pressure water descaling, enter continuous rolling in roughing mills, intermediate mill and mm finishing mill unit successively go out finished product section, wherein, tapping temperature≤1200 DEG C, mill speed≤the 18m/s of continuous casting billet in mm finishing mill unit, in four-high mill, the lengthening coefficient of one-pass roller controls between 1.15-1.4, and in two-roller mill, the lengthening coefficient of one-pass roller controls between 1.1-1.25;

(3) roll out the cored steel after finished product section and cut scale or multiple length through shearing equipment, then enter cold bed cooling;

(4) finishing process.