Cold Drawn Seamless Carbon Steel Pipe

Steel Grade/Steel Material:10# 20# Q235 Q195

Steel pipe standard:GB/T8163

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Characteristic: 

Good concentricity

Good OD and ID tolerance

High Precision

Stable quality

Smooth Roughness

 

Production Processs:

RAW MATERIAL

 ↓

INCOMING INSPECTION

           ↓

STORAGE → CUTTING→HAMMERING → PICKING LUBRICATION → CLEANING → PHOSPHORI   CLEAN

                                                                                                                                                                                          ↓

ENDS CUTTING←STRAIGHTENING←HEAT TREATMENT↔MIDDLLE CHECK↔ COLD DRAWING ← LUBRICATING                  

FINAL INSPECTION→BUNDING→STORAGE 

 

Heat Treatment: Hot Rolling & Cold Drawn

 

Tolerance of the OD &WT:

OD Tolerance:

Production Method OD Tolerance
Hot Rolling(Extrusion) ±1% or ±0.50mm
Cold Drawn(Cold Rolled) ±1% or ±0.30mm

 

Tolerance for wall thickness:

 

1.Wall thickness tolerance of Hot Rolling steel tube:

Production Method OD (DN) WT/OD Tolerance
Extruded tube ≤102 / ±12.5% or ±0.40mm
>102 ≤0.05 ±15% or ±0.40mm
>0.05-0.10 ±12.5% or ±0.40mm
>0.10 +12.5%

-10%

Heat expanding steel tube / ±15%

 

2.Wall thickness tolerance of Cold Drawn(Cold Rolled) steel tube:

Production Method WT Tolerance
Cold Drawn(Cold Rolled) steel tube ≤3 +15%/-10% or ±0.40mm
>3 +12.5%

-10%

 

Bending tolerance:

WT≤15mm, Bending≤1.5mm/m

WT>15mm~30mm, Bending≤2.0mm/m

WT>30mm/OD≥351mm, Bending≤3.0mm/m

 

Ovality and Wall unevenness:

The ovality and wall unevenness should be no more than 80% of the OD and wall thickness.(Or according to customer’s request)

 

mechanical property

Steel Grade Tensile strength

Rm

N/mm2(MPa)

Yield Strength

Rp0.2

N/mm2(MPa)

Elongation

A %

Wall Thickness
≤16mm >16~30mm >30mm
10 ≥335 ≥205 ≥195 ≥185 ≥24
15 ≥375 ≥225 ≥215 ≥205 ≥22
20 ≥410 ≥245 ≥235 ≥225 ≥20
25 ≥450 ≥275 ≥265 ≥255 ≥18
35 ≥510 ≥305 ≥295 ≥285 ≥17
45 ≥590 ≥335 ≥325 ≥315 ≥14
20Mn ≥450 ≥275 ≥265 ≥255 ≥20
25Mn ≥490 ≥295 ≥285 ≥275 ≥18
Q235 A 375~500 ≥235 ≥225 ≥215 ≥25
B
C
D
Q275 A 415~540 ≥275 ≥265 ≥255 ≥22
B
C
D
Q295 A 390~570 ≥295 ≥275 ≥255 ≥22
B
Q345 A 470~630 ≥345 ≥325 ≥295 ≥20
B
C ≥21
D
E
Q390 A 490~650 ≥390 ≥370 ≥350 ≥18
B
C ≥19
D
E
Q420 A 520~680 ≥420 ≥400 ≥380 ≥18
B
C ≥19
D
E
Q460 C 550~720 ≥460 ≥440 ≥420 ≥17
D
E