Difference between DNV E500 and DNV E550 steel plate - Knowledge

DNV E500 and E550 are shipbuilding/marine steel grades, with the primary difference being their strength, indicated by the number: E500 has a minimum yield strength of around 500 MPa, while E550 is a higher-strength grade with a minimum yield strength around 550 MPa, classifying it as an extra-high-strength steel, typically requiring Quenched & Tempered (QT) or Thermomechanical Controlled Processing (TMCP) for delivery, unlike E500 which might be normalized too.

Chemical Composition

DNV E500 extra high Strength Chemical Composition
Grade	The Element Max (%)
Grade	C	Si	Mn	P	S	Al	N
DNV E500	0.20	0.10-0.55	1.7	0.030	0.030	0.015-0.08	0.020
	Nb	V	Ti	Cu	B	Ni	Mo
	0.02-0.05	0.04-0.10	0.02		0.005

DNV E550 extra high Strength Chemical Composition
Grade	The Element Max (%)
Grade	C	Si	Mn	P	S	Al	N
DNV E550	0.20	0.10-0.55	1.7	0.030	0.030	0.015-0.08	0.020
	Nb	V	Ti	Cu	B	Ni	Mo
	0.02-0.05	0.04-0.10	0.02		0.005

Mechanical Property

DNV E500 extra high general strength property
Grade		Mechanical Property			Charpy V Impact Test
Grade	Thickness	Yield	Tensile	Elongation	Degree	Energy 1	Energy 2
DNV E500	mm	Min Mpa	Mpa	Min %	-40	J	J
	t≤50	500	610-770	16%		33	50
	50＜t≤70	500	610-770	16%		33	50
	70＜t≤150	500	610-770	16%		33	50
Note: Energy 1 is transverse impact test, Energy 2 is longitudinal

DNV E550 extra high general strength property
Grade		Mechanical Property			Charpy V Impact Test
Grade	Thickness	Yield	Tensile	Elongation	Degree	Energy 1	Energy 2
DNV E550	mm	Min Mpa	Mpa	Min %	-40	J	J
	t≤50	550	670-830	16%		37	55
	50＜t≤70	550	670-830	16%		37	55
	70＜t≤150	550	670-830	16%		37	55
Note: Energy 1 is transverse impact test, Energy 2 is longitudinal

Key Differences Summarized:

Strength: E550 is stronger (min yield 550 MPa) than E500 (min yield 500 MPa).

Application: Both are for marine/shipbuilding, but E550 targets extra-high-strength requirements.

Heat Treatment: E500 can be Normalized, TM, or QT; E550 (above 500 MPa strength) is typically TM or QT.

In More Detail:

DNV E500: A high-strength steel suitable for general hull structures, with a specified minimum yield strength (MYS) of approximately 500 MPa.

DNV E550: An Extra High Strength (EHS) steel, designed for more demanding structural parts, with a minimum yield strength of about 550 MPa, requiring advanced processing like TMCP or QT.

Think of it like vehicle performance: E500 is a powerful engine, while E550 is the next level up, offering even more strength for critical components in harsh marine environments.