Steel Tubes for structures

Structural steel tubes can be divided into hot-rolled seamless tube and welded steel pipe.
As seamless tube manufacturers, XUD STEEL could do cold drawn seamless tube manufacturing process, annealed seamless tube, cold rolled steel tube, BK+S cold drawn steel tubes, and various precision seamless steel pipe fabrication.

Low-alloy and high-strength structure pipe is widely used in many large venues, Bridges, TV towers, high-rise buildings, factories and other infrastructure construction. Steel structure steel pipe is also used in the boiler tube, superheater pipe, high pressure boiler tube, heat exchanger pipe, steam pipe industry.

Seamless steel pipe for structures

as one important application, hereinafter referred to as structural pipe, mainly used for the general structure and mechanical structure. It is usually widely used in building structures, mechanical structures, transportation, aviation, oil exploitation and other industries.

Stainless seamless pipe for structures (GB / T14975-2002)

is a hot rolled (squeeze, expansion) and cold drawn (rolled) seamless tube made of stainless steel for corrosion-resistant pipes and structural parts and parts for chemical, petroleum, light textile, medical, food, machinery and other industries.

Welded steel pipe for structure

Welded steel pipe for structure is used in steel structure, bridge support, building structure pipe, pile foundation pipe, etc. According to the usages, steel pipe can be divided into: pipeline steel pipe, thermal equipment steel pipe, mechanical steel pipe, petroleum, geological drilling steel pipe, container steel pipe, steel pipe for chemical industry, special steel pipe.

Comparison of Structural tubes between China National standard and Germany Standard.

GB/T 8162 China National standard : Seamless steel tubes for structure

DIN 1629 German Industrial standard: Seamless Circular Tubes of Non-Alloys Steels with Special Quality Requirements.

DIN 1629 seamless tubes popular steel materials: St37.0 st44.0 st55 st52.0 ck45

Materials Chemical comparison between GB/T8162 and DIN1629:

Standard	Grade	C	Si	Mn	S	Cr	Ni	Cu	V
GB/T 8162	10	0.07-0.13	0.17-0.37	0.35-0.65	≤0.025	≤0.15	≤0.30	≤0.25	""
	20	0.17-0.23	0.17-0.37	0.35-0.65	≤0.025	≤0.25	≤0.30	≤0.25	""
	35	0.32-0.39	0.17-0.37	0.50-0.80	≤0.025	≤0.25	≤0.30	≤0.25	""
	45	0.42-0.50	0.17-0.37	0.50-0.80	≤0.025	≤0.25	≤0.30	≤0.25	""
	Q345A	≤0.20	≤0.55	1.00-1.60	≤0.025	≤0.30	≤0.30	≤0.30	""
	Q345B	≤0.20	≤0.55	1.00-1.60	≤0.025	≤0.30	≤0.30	≤0.30	""
	Q345C	≤0.20	≤0.55	1.00-1.60	≤0.025	≤0.30	≤0.30	≤0.30	0.02-0.15
	Q345D	≤0.18	≤0.55	1.00-1.60	≤0.025	≤0.30	≤0.30	≤0.30	0.02-0.15
	Q345E	≤0.18	≤0.55	1.00-1.60	≤0.025	≤0.30	≤0.30	≤0.30	0.02-0.15
Q/BQB 203 DIN 1629	St37.0	≤0.17	0.17-0.37	0.35-0.65	≤0.025	≤0.020	≤0.25	≤0.25	""
	St44.0	≤0.21	0.17-0.37	0.50-0.80	≤0.025	≤0.020	≤0.25	≤0.25	""
	St55	0.33-0.41	0.17-0.37	0.50-0.80	≤0.025	≤0.020	≤0.25	≤0.25	""
	St52.0	≤0.22	≤0.55	≤1.60	≤0.025	≤0.020	≤0.25	≤0.25	""
	CK45	0.42-0.50	0.17-0.37	0.50-0.80	≤0.025	≤0.020	≤0.25	≤0.25	""

Mechanical properties:

Standard	Grade	Tensile strength (Mpa)	Yield point(Mpa) not less than		Elongation(%) not less than	Impact test
			≤16mm	>16-30mm		Temperature (°C)	Absorbed energy (KV/J)
GB/T 8162	10	≥335	205	195	24	--	--
	20	≥410	245	235	20	--	--
	35	≥510	305	295	17	--	--
	45	≥590	335	325	14	--	--
	Q345A	470-630	345	325	20	--	--
	Q345B	470-630	345	325	20	20	34
	Q345C	470-630	345	325	21	0	34
	Q345D	470-630	345	325	21	-20	34
	Q345E	470-630	345	325	21	-40	27
Q/BQB 203 DIN 1629	--	--	≤16mm	>16mm	--	--	--
	St37.0	350-480	235	225	25	--	--
	St44.0	420-550	275	265	21	--	--
	St55	540-645	295	285	17	--	--
	St52.0	500-650	355	345	21	--	--
	CK45	590-730	335	325	14	--	--