API 2Y Gr 50  Steel Plate

API 2Y Gr 50 Steel Plate

Nearest Equivalent Grade : EN10225 S460G1+Q, S460G2+Q,

BS7191:1989 450EM, 450EMZ

Characteristic :

API 2Y Grade 50 is able to resist impact, plastic fatigue loading and realhealthmethod.com lamellar tearing is ranked as High Strength Structural Steel Plate suitable for welded construction of offshore structures/offshore platforms in selected critical portions. API 2YGrade 50 has a yield strength of 344-517MPa (50-75ksi) and min tensile strength 448MPa (65ksi) for steel plates thickness ≤ 25.4 (1”). Yield strength of 414-482MPa (50-70ksi) and min tensile strength 448MPa (65ksi) for steel plates thickness ≥ 25.4mm (1”) to 150mm (6”) and both transverse Charphy V-notch impact toughness of 41J (30 ft-lbf) at -40ºC (-40ºF). API 2Y Gr50 is an offshore steel grade which is regulated by American Petroleum Institute (API) and in some cases certified by the American Bureau of Shipbuilding (ABS).

Delivery Condition : Roller Quenched and Tempered (RTQ)

API 2Y Grade50 is delivered in Roller Quenched and Tempered (RQT) condition where this high strength steel plate is heated to a temperature depending on grade, in the range from 880°C to 930°C and then water quenched using Drever Roller Pressure Quench unit. Roller Quenched and Tempered steel plate such as API 2Y Grade50 is produced by heating high quality reversing plate of the required chemical composition and thickness rolled from continuously cast slabs or direct rolled ingots of sulphur steel.

API 2Y Grade50 is quenched via Roller Quenched and Tempered (RTQ) method at very high cooling rates by large volumes of high pressure water sprayed across the full width of the plate on to both top and bottom surfaces. During the quenching operation the plates are held flat and are in continuous motion, thus ensuring that each part of the plate is cooled at the same rate. The precise rate of cooling during quenching is achieved by controlling the water pressure and the speed of passage of the plate through the unit, allowing consistent properties to be achieved in the final product. The quenching efficiency of this process is extremely high, giving the desired properties with very low levels of micro-alloying elements and low levels of CEV.

By ensuring uniform temperature distribution and close temperature control, the final levels of strength and lupo italiano org toughness are achieved by tempering heat treatments performed in furnaces. Through this method, steel plates of satisfying grades require nominal yields of 420 MPa, 450 MPa and 460 MPa can all be produced from steel slab or ingots of similar target compositions.

Thickness, t

mm [in.]

Yield Strength MPa


Tensile Strength

min MPa [ksi]

Minimum Elongation

(in 2”) / %

Minimum Average Charpy-V Impact Energy / J @ -40ºC

t ≤ 25.4 [ 1.00” ]


[ 50 - 75 ]

448 [ 65 ]



t 25.4 - 152mm

[1.00” ] - [ 6.00” ]


[ 50 - 70 ]

448 [ 65 ]

Chemical Composition (%) Unless a range is specified, individual values are maximum




































CE 0.39 to 38.1mm (1½”)

CE 0.41 to 88.9mm (3½”)

CE 0.43 to 152.4mm (6”)

TCVN Require


Our steel mill provides full range of testing facilities with standard testing requirements of each specification being professionally undertaken. Further specialist testing can be undertaken as necessary at one of our steel mill technology centers.

Our in-house NDT operators who are certified in accordance with EN473 carry out Non-destructive testing (NDT). When specified, NDT testing facility can be incorporated into the 100% inspection process, an offline activity for checking the product conformity to the standard applied. This inspection service is operated in a dedicated bay by teams of experienced steel inspectors ensuring a high level of service and quality product.


Mill certification and Inspection Certificate are respectively issued in accordance with EN10204 and Type 3.1.B. Other certifications can be supplied as per customer’s request e.g. Types 3.1.C, 3.2 and 3.1.A. Certificates are available in English, French and German.


API 2Y Gr50 high strength steel plate is similar to mild strength steels and other structural steels can be cold sheared by proportionately higher shearing power is required for any given thickness.

Plasma Cutting

Plates may be plasma cut within the operating thickness ranges of the equipment. All plasma cut edges which form part of a weld preparation should be incorporated fully into the weld. As with flame cut edges, plasma cut edges should be ground back in the regions to be bent prior to cold forming.

Flame cutting

Plates may be cut satisfactorily without preheating nor post-heating with standard oxy-gas equipment. However, attention must be paid to the selection of appropriate gas cutting procedures where fabrication codes specify maximum hardness levels. Care should be taken to ensure that flame cut edges are free from sharp notches, as these may prove detrimental to subsequent cold forming operations. Prior to cold forming, gas cut edges should be ground back in regions to be bent. In multiple cutting situations, care is required to achieve a balanced arrangement of the cutting torches to minimize plate distortion. Many fabrication standards stipulate that cut edges not fully incorporated into a weld should be ground back to remove the hard edge. It is recommended that these standards are followed.

Cold forming

Due to the higher strength level of API 2Y Gr50 steels, the power required for cold forming is proportionately greater than that required for mild steel plates of the same thickness though all types of structural steel plate described in this brochure can be readily cold formed. For the same reason, greater spring-back will be experienced for which due allowance must be made. Bending and brake press forming of API 2Y Gr50 steels should, where possible, be carried out with the axis of bending at right angles to the rolling direction. Minimum values of bending radius and of die opening for 90° bends, expressed as multiples of the plate thickness (t), are given in the following table.

Bend axis vs. rolling direction

Minimum inside bending radius

Minimum die opening







Hot Forming

As its composition nature intended, API 2Y Gr50 Quenched and Tempered high strength steels are not suitable for hot forming. Should it be necessary to consider a warm forming operation or a line heating operation, it should be performed at a temperature below 550°C and at least 50°C below the tempering temperature stated on the inspection certificate. Total heating times for single or multiple forming operations should be restricted to less than 1 hour per 25mm of plate thickness.

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