RINA Grade B Marine Steel Plate

RINA A steel is a kind of hot rolled general tensile strength steel. General-strength RINA shipbuilding steel comes in 12 grades of 3 strengths,Grade B is one of the grades. Grade B steel plates have yield strength of 235 MPa, and ultimate tensile strength of 400-520 MPa. All the RINA B shipbuilding Steel offered by Gnee can be certificated by RINA

RINA is a founding member of the International Association of Classification Societies(IACS),formed in 1968. The RINA fleet is recognized by approximately 116 international flag authorities. RINA integrated services for the complate shipping cycle including design, building, shipyard management, inspection and testing of materials/components and regular inspections to maintain the class are used by freight, ferries, ro-ro, passenger ships, yachts, cruise ships, navy, LGN and other specialist carrier vessels.

Grade A steel is the impact force subjected to 20 ° C
Grade B steel impact force at  0 ° C
Grade D steel impact force at -20 ° C
Grade E steel impact force at -40 ° C

Shot blasting service
Shot blasting is a method used to clean or polish steel when enhanced surface finishes are required. Shot blasting is used in almost every industry we serve. Especially in shipbuilding, rail,structural fabrication and more.

Specifications range
Thickness:2.5-120mm
Width:1000-3000mm
Length: As request

 

Chemical Composition

Steel grade	C	Si	Mn	P	S	Als
Grade A	≤0.21	≤0.50	≥2.5C	≤0.035	≤0.035	-
Grade B	≤0.21	≤0.35	0.8-1.2	≤0.035	≤0.035	-
Grade D	≤0.21	≤0.35	0.6-1.2	≤0.035	≤0.035	≥0.015
Grade E	≤0.18	≤0.35	0.7-1.2	≤0.035	≤0.035	≥0.015

Processing for Different Grades
Grade D, E (DH32, DH36, EH 32, EH 36)
Grade D and E series (inlcuding AH32/36, DH32, DH36, EH32, EH36) shipbuilding steel plates require good low temperature toughness and good welding performance. The production high-strength shipbuilding steel plate needs to be normalized by means of controlled rolling and controlled cooling or heat treatment processes with more complete equipment. At the same time, the internal steel purity of the supplied billets is required to be high, especially the content of S, P, N, 0 and H in the steel should be strictly controlled.

Alloy Elements Added to Improve Toughness
In order to ensure the performance of high-strength ship plates, micro-alloying technology is adopted. By adding Nb, V, Ti and other alloying elements to the steel, combined with the controlled rolling process, the grain is refined and the toughness is improved.

Direction of Development for Shipbuilding Plate
High strength, high specification, with the ship's large-scale and safety, and changes in coating specifications, the demand for ordinary A-class panels is gradually reduced, and the demand for high-strength panels is increasing, which is concentrated in large ships of 5m wide. Plate, 200-300mm thickness special thick ship board.

Mechanical Properties

Steel grade Yield point/MPa Tensile point /MPa Elongation/% Temperature/° C V-type impact test Akv/J ≤50MM 50-70MM 70-100MM Grade A 235 400-520 ≥22 20 - 34/24 41/27 Grade B 235 400-520 ≥22 0 27/20 34/24 41/27 Grade D 235 400-520 ≥22 -20 27/20 34/24 41/27 Grade E 235 400-520 ≥22 -40 27/20 34/24 41/27