Difference between P295GH and P355GH steel plate - Knowledge

P295GH and P355GH are normalized, non-alloy steel plates from the EN 10028-2 standard, primarily used for boilers, pressure vessels, and heat exchangers due to their excellent weldability and properties at elevated temperatures.

The key difference lies in their strength: P295GH offers a minimum yield strength around 295 MPa (depending on thickness), while P355GH is stronger, typically featuring a minimum yield strength of 355 MPa (also varying with thickness), making it suitable for more demanding high-pressure applications.

Chemical Composition

P295GH Chemical Composition
Grade	The Element Max (%)
Grade	C	Si	Mn	P	S	Al(min)	N
P295GH	0.08-0.20	0.40	0.80-1.50	0.025	0.015	0.020	0.012
	Cr	Cu	Mo	Nb	Ni	Ti	V
	0.30	0.30	0.08	0.020	0.30	0.03	0.02

Carbon Equivalent: Ceq = 【C+Mn/6+(Cr+Mo+V)/5+(Ni+Cu)/15】%

P355GH Chemical Composition
Grade	The Element Max (%)
Grade	C	Si	Mn	P	S	Al(min)	N
P355GH	0.10-0.22	0.60	1.10-1.70	0.025	0.015	0.020	0.012
	Cr	Cu	Mo	Nb	Ni	Ti	V
	0.30	0.30	0.08	0.040	0.30	0.03	0.02

Mechanical Property

Grade		P295GH Mechanical Property
Grade	Thickness	Yield	Tensilmie	Elongation	Impact Energy(KV J) min
P295GH	mm	Min Mpa	Mpa	Min %	-20°	0°	+20°
	≤ 16	295	460-580	21	27	34	40
	16> to ≤40	290	460-580	21	27	34	40
	40> to ≤60	285	460-580	21	27	34	40
	60> to ≤100	260	460-580	21	27	34	40
	100> to ≤150	235	440-570	21	27	34	40
	150> to ≤250	220	430-570	21	27	34	40

Grade		P355GH Mechanical Property
Grade	Thickness	Yield	Tensilmie	Elongation	Impact Energy(KV J) min
P355GH	mm	Min Mpa	Mpa	Min %	-20°	0°	+20°
	≤ 16	355	510-650	20	27	34	40
	16> to ≤40	345	510-650	20	27	34	40
	40> to ≤60	335	510-650	20	27	34	40
	60> to ≤100	315	490-630	20	27	34	40
	100> to ≤150	295	480-630	20	27	34	40
	150> to ≤250	280	470-630	20	27	34	40

Key Characteristics:

Standard: EN 10028-2 (for pressure vessels).

Material Type: Non-alloy steel with specified elevated temperature properties.

Applications: Boilers, pressure vessels, heat exchangers, piping in the oil & gas industry.

Properties: Good weldability, toughness, and resistance to elevated temperatures.

Comparison:

P295GH: Lower strength grade, often with a minimum yield strength around 295 MPa.

P355GH: Higher strength grade, with a minimum yield strength of 355 MPa for thinner plates, decreasing slightly with thickness.

In essence, P355GH offers higher strength for heavier-duty applications compared to P295GH, while both excel in high-temperature, high-pressure environments.