Difference between LR DH46 and LR DH50 steel plate

Dec 18, 2025 ترك رسالة

LR DH46 and LR DH50 are Lloyd's Register (LR) classified shipbuilding steels, with the primary difference being their strength: DH46 offers a minimum yield strength of 460 MPa, while DH50 provides higher strength with a minimum yield of 500 MPa, achieved through similar controlled compositions but differing amounts of alloying elements (like C, Mn, Si) and strict heat treatments (normalized) for enhanced toughness and weldability in marine structures, making DH50 suitable for more demanding applications.

LR: Lloyd's Register, the classification society.

D: High Strength.

H: Normalized (Heat Treated).

46/50: Minimum Yield Strength in kgf/mm² (or 460/500 MPa).

LR DH46 extra high Strength Chemical Composition

	C			P	S		N
LR DH46	0.20	0.55	1.70	0.030	0.030	0.015	0.020
		V
	0.02-0.05	0.03-0.10	0.02

LR DH50 extra high Strength Chemical Composition

	C			P	S		N
LR DH50	0.20	0.55	1.70	0.030	0.030	0.015	0.020
		V
	0.02-0.05	0.03-0.10	0.02

LR DH46 extra high strength property

						Energy 1	Energy 2
LR DH46					-20	J	J
	t<=50	460	570-720	19%		31	46
	50＜t<=70	460	570-720	19%		31	46
	70＜t<=100	460	570-720	19%		31	46
Note: Energy 1 is transverse impact test, Energy 2 is longitudinal

LR DH50 extra high strength property

						Energy 1	Energy 2
LR DH50					-20	J	J
	t<=50	500	610-770	18%		33	50
	50＜t<=70	500	610-770	18%		33	50
	70＜t<=100	500	610-770	18%		33	50
Note: Energy 1 is transverse impact test, Energy 2 is longitudinal

Equivalent steel grade of LR DH46

NV D460	GL-D460	AB/DQ47	BV/D460	CCS/D460	K D47	R D47	RI/D460

Equivalent steel grade of LR/DH50

NV D500	GL-D500	AB/DQ51	BV/D500	CCS/D500	K D51	R D51	RI/D500