|
|
|
|
|
Manufacturing Process
|
|
|
|
|
|
Picking & Coating
|
|
The hot-rolled coil or wire rod passes through the pickling line, where
hydrochloric acid
solution is used to remove surface scale for clean
surface finish before further processing
and to form a lubrication film on
the surface to reduce the coefficient of friction in the
drawing and cold
working process.
The Gantry Crane moves between the tank during the
process
|
|
|
|
Intermediate Drawing
|
|
This process which produces half-finished products for the following stage
improves the
spherodized ratio during spheroidized annealing. The wire
drawing machine composed of
(Supply Stand + Drawing Drum + Take up) stages
produces half-finished coil products. |
|
|
|
Spheroidized Annealing
|
|
This annealing process with the purpose of obtaining spheroidized carbides
facilitates the cold works. Once inserted in the heat treatment furnace,
the process takes place in the order of controlled heating up to a given
time, temperature and furnace atmosphere, along with maintenance at such
temperature during a certain period and cooling controlled in accordance
with the purpose intended. This process is controlled by automatic heat
cycle.
Dongbu Steel offers 54 heat cycles. |
|
|
|
Skin Pass
|
|
The wire drawing machine produces half-finished coils where products meet the
customers'
needs in terms of the size and mechanical properties of
products |
|
|
|
Steel Type Quality Characteristics
|
|
Classification by Mechanical Properties
|
| Class Symbol
|
Process |
T/S
(Tension Strength) |
HRB
(Hardness) |
Remarks |
| SWCH25K |
SA |
46 under |
72 under |
SKP:5% max.
WD:15% max. |
| (R)AIP |
72 under |
97 under |
| (S)AIP |
68 under |
94 under |
| SAF |
46 under |
72 under |
| SAIP |
50 under |
85 under |
| SWCH45K |
SA |
54 under |
82 under |
SKP:5% max.
WD:15% max. |
| (R)AIP |
72 under |
97 under |
| (S)AIP |
68 under |
94 under |
| SAF |
54 under |
86 under |
| SAIP |
56 under |
92 under |
| PSASAIP |
54 under |
86 under |
| SCM435 |
SA |
58 under |
86 under |
SKP:5% max
WD:15% max |
| (R)AIP |
75 under |
99 under |
| (S)AIP |
72 under |
97 under |
| PASAF |
56 under |
92 under |
| PASAIP |
58 under |
92 under |
| PSASAIP |
56 under |
90 under |
|
|
|
|
Classification by Cemical Components
|
| Class
Symbol |
Chemical
Composition(%) |
Remarks |
| C |
Si |
Mn |
P |
S |
AI |
| SWRCH 6A |
0.08 max |
0.10 max |
0.30-0.60 |
0.030 max. |
0.035 max. |
0.02 min. |
Aluminium
Killed Steel |
| SWRCH 8A |
0.10 max |
0.10 max |
0.30-0.60 |
0.030 max. |
0.035 max. |
0.02 min. |
| SWRCH 10A |
0.08-0.13 |
0.10 max |
0.30-0.60 |
0.030 max. |
0.035 max. |
0.02 min. |
| SWRCH 12A |
0.10-0.15 |
0.10 max |
0.30-0.60 |
0.030 max. |
0.035 max. |
0.02 min. |
| SWRCH 15A |
0.13-0.18 |
0.10 max |
0.30-0.60 |
0.030 max. |
0.035 max. |
0.02 min. |
| SWRCH 16A |
0.13-0.18 |
0.10 max |
0.60-0.90 |
0.030 max. |
0.035 max. |
0.02 min. |
| SWRCH 18A |
0.15-0.20 |
0.10 max |
0.60-0.90 |
0.030 max. |
0.035 max. |
0.02 min. |
| SWRCH 19A |
0.15-0.20 |
0.10 max |
0.70-1.00 |
0.030 max. |
0.035 max. |
0.02 min. |
| SWRCH 20A |
0.18-0.23 |
0.10 max |
0.30-0.60 |
0.030 max. |
0.035 max. |
0.02 min. |
| SWRCH 22A |
0.18-0.23 |
0.10 max |
0.70-1.00 |
0.030 max. |
0.035 max. |
0.02 min. |
| SWRCH 10K |
0.08-0.13 |
0.10 max |
0.30-0.60 |
0.030 max. |
0.035 max. |
- |
Killed Steel |
| SWRCH 12K |
0.10-0.15 |
0.10-0.35 |
0.30-0.60 |
0.030 max. |
0.035 max. |
- |
| SWRCH 15K |
0.13-0.18 |
0.10-0.35 |
0.30-0.60 |
0.030 max. |
0.035 max. |
- |
| SWRCH 16K |
0.13-0.18 |
0.10-0.35 |
0.60-0.90 |
0.030 max. |
0.035 max. |
- |
| SWRCH 17K |
0.15-0.20 |
0.10-0.35 |
0.30-0.60 |
0.030 max. |
0.035 max. |
- |
| SWRCH 18K |
0.15-0.20 |
0.10-0.35 |
0.60-0.90 |
0.030 max. |
0.035 max. |
- |
| SWRCH 20K |
0.18-0.23 |
0.10-0.35 |
0.30-0.60 |
0.030 max. |
0.035 max. |
- |
| SWRCH 22K |
0.18-0.23 |
0.10-0.35 |
0.70-1.00 |
0.030 max. |
0.035 max. |
- |
| SWRCH 24K |
0.19-0.25 |
0.10-0.35 |
1.35-1.65 |
0.030 max. |
0.035 max. |
- |
| SWRCH 25K |
0.22-0.28 |
0.10-0.35 |
0.30-0.65 |
0.030 max. |
0.035 max. |
- |
| SWRCH 27K |
0.22-0.29 |
0.10-0.35 |
1.20-1.50 |
0.030 max. |
0.035 max. |
- |
| SWRCH 30K |
0.27-0.33 |
0.10-0.35 |
0.60-0.90 |
0.030 max. |
0.035 max. |
- |
| SWRCH 33K |
0.30-0.36 |
0.10-0.35 |
0.60-0.90 |
0.030 max. |
0.035 max. |
- |
| SWRCH 35K |
0.32-0.38 |
0.10-0.35 |
0.60-0.90 |
0.030 max. |
0.035 max. |
- |
| SWRCH 38K |
0.35-0.41 |
0.10-0.35 |
0.60-0.90 |
0.030 max. |
0.035 max. |
- |
| SWRCH 40K |
0.37-0.43 |
0.10-0.35 |
0.60-0.90 |
0.030 max. |
0.035 max. |
- |
| SWRCH 41K |
0.36-0.44 |
0.10-0.35 |
1.35-1.65 |
0.030 max. |
0.035 max. |
- |
| SWRCH 43K |
0.40-0.46 |
0.10-0.35 |
0.60-0.90 |
0.030 max. |
0.035 max. |
- |
| SWRCH 45K |
0.42-0.48 |
0.10-0.35 |
0.60-0.90 |
0.030 max. |
0.035 max. |
- |
| SWRCH 48K |
0.45-0.51 |
0.10-0.35 |
0.60-0.90 |
0.030 max. |
0.035 max. |
- |
| SWRCH 50K |
0.47-0.53. |
0.10-0.35 |
0.60-0.90 |
0.030 max. |
0.035 max. |
- |
|
|
|
|
|
|
Product Guarantee Availability
|
|
Dimenstion
|
Manufacturing
Process Symbol |
Size |
Tolerance |
Out-of-round |
| R, RA, SA |
10 less
10 ~ 16
16 more
than |
± 0.4
± 0.4
± 0.5 |
0.4
less
0.5 less
0.6 less |
AIP, SAIP
PASAIP
PSASAIP |
10 less
10 ~ 16
16 more
than |
0, -0.03
0, -0.04
0, -0.05 |
0.01 less
0.015 less
0.025 less |
SAF,
PASAF |
10 less
10 ~ 16
16 more
than |
± 0.3
± 0.4
± 0.5 |
0.03 less
0.04 less
0.05 less |
| Hexagonal |
10 less
10 ~ 16
16 more
than |
0, -0.08
0, -0.09
0, -0.10 |
0.02 less
0.025 less
0.03 less |
|
|
|
|
Decarburization Depth
|
| Symbol |
Carbon
Steel |
Alloy
Steel |
Manufacturing
Process |
Size(mm) |
DM-F |
DM-T |
DM-F |
DM-T |
| RA, SA |
10 less
10 more
than |
0.04
0.05 |
0.15
0.20 |
0.04
0.05 |
0.15
0.20 |
SAF,
PASAF |
8 less
8 ~ 14
14 ~ 20
20 more
than |
0.04
0.05
0.06
0.07 |
0.15
0.20
0.20
0.25 |
0.03
0.04
0.05
0.06 |
0.12
0.15
0.20
0.25 |
SAIP
PASAIP |
8 less
8 ~ 14
14 ~ 20
20 more
than |
0.03
0.04
0.05
0.06 |
0.12
0.15
0.20
0.20 |
0.02
0.03
0.04
0.05 |
0.10
0.12
0.15
0.20 |
|
|
* DM-F : Decarburization Microscope Ferrite
* DM-T : Decarburization
Microscope Total |
|
|
|
Spheroidized Ratio
|
Manufacturing
Process Symbol |
Spheroidized Ratio(%) |
| RA, (R)AIP |
- |
| SA, (S)AIP, SCD |
70 ± 10 |
| SAF, SAIP, PASAF, PASAIP, SWCD |
80 Over |
| PSASAIP, SWSCD |
90 Over |
|
|
|
|
Mechanical Properties
|
| Steel
|
Manufacturing
Process Symbol |
Tensil
Strength
(Kg/㎟) |
Reduction
of Area
(%) |
Remarks |
| SWCH45K |
RA
SA
(R)AIP
(S)AIP
SAF
SAIP
PSASAIP |
64 or
less
60 or less
72 or
less
68 or less
58 or
less
62 or less
56 or
less |
60 or
more
63 or more
55 or more
60 or
more
65 or more
62 or more
65 or
more |
단면감소율
12%Max |
|
|
|
|
|
|
|
