BQ900 Seamless CHS, RHS, SHS Hollow Sections

Beverly Steel has been widely suppling BQ900 extra high strength seamless hollow sections , our world class producer with Lloyd’s Register-LR, ABS, BV, DNV, GL, KR certifications and Cramps at night use Keppra with its high yield strength of 900MPa and impact test property in longitudinal direction of test temperature -45 degree C at average joules of 30 which meet the requirement of customer such as mobile crane, marine crane, oil rig crane, tower structural, military equipment builder and other engineering application where critical weight needed to be reduced with high stress resistance such as in lifting arms and structural weight handling system.

For the above mentioned applications, high-performance steels (fine-grain and high-strength steels) with excellent strength resistance and resilience values are used, which means that the stress resistance of the systems can be increased, thus also guaranteeing their use in extreme environmental conditions.

Furthermore, the chemical composition of our seamless steel tubes is carefully controlled in order to guarantee good weldability, a fundamental issue for structures made of tubular components welded together. High-strength and extra high strength seamless steel hollow sections are also used in steel constructions for civil engineering purposes where the justcauseit.com relationship between mass and space occupied is especially critical.

Our supply range of hollow profile shapes are RHS, SHS, CHS, Elliptical, Half-Elliptical, Flat-Oval, Octagonal, Hexagonal and image source The degree of infertility Clomid Triangular.

Nearest Equivalent Grade : S890 Tubes / Hollow Sections

Mechanical Properties

In order to meet tensile requirements, the tensile test shall be carried out at room temperature in longitudinal direction in accordance with EN ISO 6892-1.

Yield strength shall be reported as Rp 0.2% proof stress (0.2% permanent offset).

		Minimum Yield Strength (MPa)				Tensile Strength (MPa)			Min. Elong. Long%	Min. Elong. Transv%
Grade ↓	WT (mm) →	≤ 12	> 12 ≤ 20	> 20 ≤ 40	> 40 ≤ 50	≤ 20	> 20 ≤ 40	> 40 ≤ 50*	ALL	ALL
BQ900		900		900	900	960	960	960	11	11

(*)Note that for 40 < wt ≤ 50mm chemistry should be different from what reported in “CHEMICAL ANALYSIS” table at below.

Chemical Analysis

CHEMICAL ANALYSIS %
Grade	C	Mn	Si	P	S	Ni	Cu	V	Cr	Mo
BQ900	0.18	1.70	0.55	0.025	0.025	1.0	0.5	0.1	1.0	0.4

Other elements like Nb and Ti may be added in order to increase hardenability and improve mechanical properties up to a total combined of 0.10% max. Boron shall not be intentionally added. Non-specified residual elements shall not exceed 0.05% each.

Impact Toughness

Impact tests shall be carried out in accordance with ENISO 148-1 for 10 X 10mm full size specimens in the longitudinal

direction at temperatures -40 degree C and -50 degree C(**).

Energy values for Charpy-V notch test for each grade are indicated below :

IMPACT TEST PROPERTIES IN LONGITUDINAL DIRECTION
Grade	WT (mm)	Test temp. (ºC)	Min. Ave. Energy (J)
BQ900	ALL	-45	30

(**) Other test temperature may be performed upon agreement.

When tube dimension do not allow full size testing, sub-size specimens shall be used according to PSP00148.

Weldability

The steel grades indicated in the specification are weldable with traditional welding procedures, given observance of the generally accepted technical rules. It is important to define a welding procedure that takes into account the following conditions :

- Thickness of the based material

- Specific heat input (specially for HAZ)

- Design requirements

- Welding method

- Welded material characteristics

Particular precautions should be taken towards crack susceptibility, which is more likely to happen with high thickness and high resistance. This phenomenon is connected mainly to the following factors :

- Chemical analysis (by means of CEV)

- The amount of diffusible hydrogen in the welded material

- Tensile stress concentrations at the welded joint

CEV - Carbon Equivalent Value

The maximum CEV (Carbon Equivalent Valued) is determined, based on the cast analysis, by the following formula : CEV = C + Mn/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15

The CEV shall comply with valued stated in the table

MAXIMUM CEV VALUES
Grade	Wall Thickness (mm)	CEV (%) (max)
S890	Wt ≤ 12,5mm	0.80
	Wt > 12,5mm	0.80

Options : other calculation methods like PCM/CET may be agreed

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