Shipbuilding steel pipe

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03-Jun-2024

GB T 5312 Carbon and carbon-manganese steel seamless steel tubes and pipes are mainly for ship use, also known as shipbuilding steel pipes. Under GB T 5312, there are mainly 5 steel grades: grade 320, 360, 410, 460 and 490. Each grade covers three levels: I, II, III.

Approved classification society: ABS, LR, BV, DNV GL, RINA, CCS, NK, KR

GB T 5312 shipbuilding steel pipe chemical composition: %

Grade	C	Si	Mn	S	P	Residual elements
						Cr	Mo	Ni	Cu	Total
320	≦0.16	-	0.40~0.70	≦0.020	≦0.025	≦0.25	≦0.10	≦0.30	≦0.30	≦0.70
360	≦0.17	≦0.35	0.40~0.80
410	≦0.21	≦0.35	0.40~1.20
460	≦0.22	≦0.35	0.80~1.20
490	≦0.23	≦0.35	0.80~1.50

GB T 5312 shipbuilding steel pipe mechanical properties:

Grade	Tensile strength (Mpa)	Yield strength (Mpa)	Elongation (%)
320	320-440	≧195	≧25
360	360-480	≧215	≧24
410	410-530	≧235	≧22
460	460-580	≧265	≧21
490	490-610	≧285	≧21

shipbuilding steel pipe

GB T 5312 shipbuilding steel pipe grade level:

Grade level	Grade I		Grade II		Grade III
Media	Design Pressure / Mpa	Design temperature / ℃	Design Pressure / Mpa	Design temperature / ℃	Design Pressure / Mpa	Design temperature / ℃
Media	>		-		≦
Steam and Hot Oil	1.6	300	0.7-1.6	170-300	0.7	170
fuel	1.6	150	0.7-1.6	60-150	0.7	60
Other media	4.0	300	1.6-4.0	200-300	1.6	200
Note 1: When one of the design pressures and temperatures of the pipe meet the requirements of Class I in the table, it is designated as Class I. When both the design pressures and design temperatures of the pipe meet the requirements of Class II in the table, it is designated as Class II. Note 2: Other media refer to air, water, lubricating oil and hydraulic oil, etc.. Note 3: Seamless steel pipes for Class III piping systems can be manufactured in accordance with the national standards approved by the ship inspection department.

GB T 5312 shipbuilding steel pipe application
GB T 5312 shipbuilding steel pipes are used for the manufacture of marine boilers and superheater I, II, III pressure pipe system tubes, as well as the manufacture of LPG transport and bulk chemical ship pipes. The working temperature of GB T 5312 shipbuilding steel pipes wall is no more than 450 degrees.