GB9948 Cold Drawn 20# Alloy Carbon Pipe Petroleum Cracking Steel Tube

GB9948 20# Alloy Carbon Pipe Petroleum Cracking Seamless Steel Tube

Production Method of Steel:

High quality carbon sructural steel and alloy structural steel should be handled through electric arc furnace and refining outside the furnace and vacuum refining processing.,also can be producetd by electroslag heavy solvent method.Stainless steel should use electric arc furnace and refining outside the furnace or oxygen converter refining outside the furnace,also can be producetd by electroslag heavy solvent method.

Production Method of Steel:

Hot Rolling(Extrusion,Expansion)or Cold Drawn(Rolling).

Size:

OD:20-500mm

WT:2-50mm

Length:4-12m

Delivery State:

Steel pipes should be delivery with hot treatment state.

Application:

Petrochemical industry furnace tube

Heat exchanger tube

Seamless steel tube for pressure pipe use

The Tolerances of Outer Diameter and Wall Thickness Unit:mm

Sort Code	Manufacuring Method	Nominal Size		Tolerances
				Common Level	High Level
W-H	Hot Rolling (Extrusion)	Outer Diameter D	≤54	±0.50	±0.30
			>54~325	±1%D	±0.75%D
			>325	±1%D	-
		Wall Thicknass S	≤20	+15%S -10%S	±10%S
			>20	+12.5%S -10%S	±10%S
	Hot Expand	Outer Diameter D	All	±1%D
		Wall Thicknass S	All	±15%S
W-C	Cold Drawn(Rolling)	Outer Diameter D	≤25.4	±0.15
			>25.4~40	±0.20
			>40~50	±0.25
			>50~60	±0.30
			>60	±0.75%D	±0.5%D
		Wall Thicknass S	≤3.0	±0.3	±0.2
			>3.0	±10%S	±7.5%S

 

           Testing items and sampling quantity of steel tubes

Number	Testing items	Sampling quantity
1	Chemical composition	1 sample from each furnace
2	Tensile test	1 sample from each of two steel tubes on each batch
3	Hardness test	3 samples taken on 2 steel tubes on each batch
4	Impact test	All
5	Hydraulic test	1 sample from each of two steel tubes on each batch
6	Flattening test	2 samples taken on 2 steel tubes on each batch
7	Bending test	1 sample taken on 2 steel tubes on each furnace
8	Flaring test	2 samples taken on 2 steel tubes on each batch
9	Macroscopic examination	1 sample taken on 2 steel tubes on each furnace
10	Non-metallic inclusions	1 sample taken on 2 steel tubes on each furnace
11	Eddy current testing	All
12	Magnetic flux leakage detection	All
13	Ultrasonic testing	All
14	Intergranular corrosion test	1 sample from each of two steel tubes on each batch