Computation Sheet for Beam 125 × 70 MM

Computation Sheet for Flange

Table 10.2

Pass

No.

Flange Dimensions

Flange

Flange

Height

hf

mm

Root

Thickness

Rt

mm

Tip

Thickness

tt

mm

Flange Area ff mm2

Coff. of Elongation

Pull Down h mm

Height Increments In mm

12th

Dead

33.5

  • 10.2
  • (103)

5.6

264

1.05

1.5

Live

34.0

  • 10.1
  • (102)
  • 5.5
  • (1.09)

265

1.00

+1.5

10th

Dead

32.5

  • 10.3
  • (1.065)

6.0

265

1.11

2.5

Live

35.0

  • 10.5
  • (1.105)
  • 5.4
  • (1.165)

278

1.16

+1.0

9th

Dead

34.0

  • 11.6
  • (1.05)

6.3

322

1.08

4.0

Live

35.0

  • 11.0
  • (1215)
  • 5.8
  • (1 275)

294

1.27

+1.0

8th

Dead

34.0

  • 13.4
  • (1.06)

7.4

374

1.12

3.0

Live

38.0

  • 12.2
  • (126)
  • 6.1
  • (139)

348

1.34

+1.0

6th

Dead

37.0

  • 15.4
  • (113)

8.5

467

1.16

7.0

Live

39.0

  • 14.2
  • (1.365)
  • 7.1
  • (1.505)

416

1.43

+1.0

5th

Dead

38.0

  • 19.4
  • (1.155)

10.7

595

1.17

6.0

Live

43.0

  • 17.4
  • (1.45)
  • 8.3
  • (163)

544

1.49

+1.0

3rd

Dead

42

  • 25.2
  • (121)

13.5

813

1.25

4.0

Live

42

  • 22.4
  • (148)
  • 10.6
  • (170)

693

1.52

+1.0

2nd

Dead

41

33.2

18

1050

Live

46

30.5

14.0

1011

0

Fig. under brackets show the co-efficient of reduction of different elements

Computation for The Web

Table 10.3

Pass

No.

Web Dimensions

Web Deformation

Width

В

mm

Thickness d mm

Web Area

FW

mm2

Coff. of Elongation p

Draught

Ahw

mm

Spread

Abw

mm

12th

124

  • 4.6
  • (1.04)

571

1.035

0.2

1.0

10th

123

  • 4.8
  • (1.08)

591

1.07

0.4

1.5

9th

121.5

  • 5.2
  • (1.15)

632

1.14

0.8

1.5

8th

120

  • 6.0
  • (1.25)

720

1.23

1.5

2.0

6th

118

  • 7.5
  • (1.45)

885

1.37

3.0

2.5

5th

115.5

  • 10.5
  • (1.62)

1212

1.58

6.5

3.5

3rd

112

  • 17
  • (1.88)

1904

1.88

15

4.0

2nd

108

32

3584

1.18

8.0

Fig. under brackets show the co-efficient of reduction of different elements

Computation for Pass height, Pass Area

Table 10.4

Pass

No.

Full

Height of Pass H mm

Total Height Pull Down

Pass Area F mm2

Co-efficient of Elongation for Whole Pass m

12th

72.1

.2

1660

1.05

10th

72.3

1.9

1750

1.11

9th

74.2

3.8

1940

1.17

8th

78.0

5.5

2270

1.23

6th

83.5

7.0

2800

1.31

5th

91.5

9.5

3670

1.48

3rd

101

18

5430

1.51

2nd

119

8200

Pass Design of Beam 125 × 70

Pass Design of Finishing Stand (12th)

The pass design and roll design of stand-12 has been done, as shown in Fig. 10.18 and 10. 19 below':

Finishing Pass (Pass-12)

Fig. 10.18 Finishing Pass (Pass-12).

Roll Diagram of Stand-12

Fig. 10.19 Roll Diagram of Stand-12.

Design of Pre-finishing Stand (10th)

The pass design and roll design of stand-10 has been done, as shown in Fig. 10.20 and 10.21 below':

Pre-finishing Pass-10

Fig. 10.20 Pre-finishing Pass-10.

Roll Diagram of Stand-10

Fig. 10.21 Roll Diagram of Stand-10.

Design of Strand Pass (9th)

The pass design and roll design of stand-8 has been done, as shown in Fig. 10.22 and 10.23 below:

Strand Pass-9

Fig. 10.22 Strand Pass-9.

Roll Diagram of Stand-09

Fig. 10.23 Roll Diagram of Stand-09.

Intermediate Group (Stand-8)

The pass design and roll design of stand -8 has been done, as shown in Fig. 10.24 and 10.25 below:

Roll Diagram of Stand-08

Fig. 10.25 Roll Diagram of Stand-08.

Intermediate Group (Stand-6)

The pass design and roll design of stand-6 has been done, as shown in Fig. 10.26 and 10.27 below:

Roll Diagram of Stand-06

Fig. 10.27 Roll Diagram of Stand-06.

Design of Pass-5

The pass design and roll design of stand-5 has been done, as shown in Fig. 10.28 and 10.29 below:

Roll Diagram of Stand-05

Fig. 10.29 Roll Diagram of Stand-05.

Design of Pass-3

The pass design and roll design of stand-3 has been done, as shown in Fig. 10.30 and 10.31 below:

Roll Diagram of Stand-03

Fig. 10.31 Roll Diagram of Stand-03.

Design of Pass-2 (“V”Pass)

The pass design and roll design of stand -2 (“P’ Pass)_has been done, as shown in Fig. 10.32 and 10.33 below':

U-12

Fig. 10.33 Roll Diagram of Stand-2.

Design of Pass -1

The pass design and roll design of stand-1 (Box Pass) has been done, as shown in Fig. 10.34 below:

Pass Diagram of Stand-1

Fig. 10.34 Pass Diagram of Stand-1.

Rolling Scheme for Beam 125 × 70

Input Beam Blank Size- 122 x 135 x 80 nun x 6 m length

Table 10.5

Stand

H

В

d

t

Dk

N

i

Dc

1

100

140

30

451

300

9.58

515/515

Tilter 90°

2

119

108

32

12

508

300

8.12

551/505

3

101

112

17

9

523

380

6.96

502/560

4

-

-

-

-

-

-

3.51

-

5

91.5

115.5

10.5

7

529.5

378

4.69

560/506

6

83.5

118.2

7.5

5

428

346

2.90

410/460

7

-

-

-

-

-

-

-

8

78.0

120.2

6.0

5

430

300

2.026

460/410

9

74.2

121.7

5.2

4

432

300

1.88

412/460

10

72.3

123.2

4.8

4

432

300

1.59

460/412

11

-

-

-

-

-

-

-

12

70

124

4.6

4

385

300

1.15

367/405

Note : H- Height of Stock, В -Width of Stock, d- Web thickness t- Roll gap, DK-Rolling Diameter, N- Motor Speed Dc -collar Diameter, i -Reducer Ratio .

Mill Setting of Beam

General rules of Mill setting for beam profile.

  • 1. Billets/blooms for rolling beam should be free from scabs and cracks and should have smooth surface. If size of scabs exceeds 20 mm, then such billets/blooms should be rejected at storage yard
  • 2. Billets/blooms with bad, uncroped front or tail end, should be rejected on the charging device itself.
  • 3. Temperature of metal at roughing group should not be less than 1100°C. Billets, which lie near or before the discharge door of furnace (2-4 pieces) should atleast be returned, before the start of the rolling, as these billets are usually cold.
  • 4. Selection of passes on stands is to be made by the Opm. I/c and Shift Foreman (Opr.), in a shift, incase of emergency. Checking of the close part of the pass (groove) is to be made with the help of templates. The width of the previous pass should always be less than the width of the next pass or in certain cases like cutting-in pass, may be kept equal to that. It is forbidden to use passes of the previous stand with width more than of the next. The information about the width of passes received from the roll turning shop should again be counter checked in the shop.
  • 5. While fixing the gap between rolls, special attention should be paid to the accuracy of the gap at the end runners of rolls.
  • 6. Final setting of the rolling tackles is be done only after the final setting of gap between the rolls and checking the same with filler gauge.
  • 7. Entry and delivery guides should be fitted according to the maximum width of the closed pass of every stand.
  • 8. In case considerable changes of gap between rolls is required during the process of mill setting, then it will also be necessary to check the setting of guards again.
  • 9. At the time of mill setting, dimensions of the bar should be checked at places, where measurements can be directly taken on the hot metal, otherwise, piece is to be rejected for checking of dimensions after each group i.e., roughing, intermediate and finishing group of mill. Piece after pre-finishing stand may not be rejected, as in this case, sample can be taken from the saw, keeping finishing stand in idle running. During checking the following dimensions should be checked:
    • (a) The web thickness,
    • (b) The flange height,
    • (c) Approx, flange thickness.

After the final adjustment of mill, slight changes in reduction is only allowed be allowed after judging the loads on stand.

10. Final estimate of the section, in case of beam may be arrived after examination and checking of the dimensions of the sample and pieces at cooling beds. When rolling beams, it is necessary to stop the flow of water on the bar in stands of intermediate and finishing group, otherwise the web gets cooled easily.

 
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