Continuously cast steel blooms

Steel blooms and billets are the starting materials for production of seamless steel tubes. In addition to the production of tubes they can also be used to produce other metallurgical semi-finished products using hot forming (rolling, forging, pressing, etc.). Steel blooms are made of a square or circular cross section.

Steels

All steel is cast as killed. Chemical composition of steels corresponds to individual standards and steel grades.

Chemical composition boundary of steels of steel blooms is in the range:

The elements content in weight %
	C	Mn	Si	Cr	Mo	Ni	V	S	P
min	0,05	0,3	0,1	0,05	0,05	max	0	max	max
max	1,2	2,5	1,3	2,5	1,1	3,40	0,8	0,035	0,035

The elements content in weight %
	Cu	Sn	Al	Ti	B	Nb	N	O
min max	max 0,40	max 0,040	0,005 0,050	0 0,050	0 0,001	0 0,050	0 0,01	0 0,0035

Supply conditions and the surface of steel blooms

After casting blooms are not heat treated. The surface corresponds to the method of casting and meets the requirements that are included in the agreed technical delivery regulations.

Blooms of square cross-section

Square side [mm]	Dimensional tolerance [mm]	Sidelong max* [mm]	Cross-section area [sqmm]	Weight [kg/m]	Edge of the bloom customization [mm]
105	± 3	± 4	11 000	86,0	R = 2,5 mm ± 1 mm
125	± 3	± 5	15 600	121,5	R = 3 mm ± 1 mm
150	± 3	± 6	22 420	175,5	R = 3,5 mm ± 1 mm
160	± 3	± 6	25 600	198,0	R = 4,5 mm ± 1 mm
180	± 3	± 7	32 100	253,5	R = 5,5 mm ± 1 mm
200	± 4	± 7	39 680	312,0	R = 6,5 mm ± 1 mm
205	± 4	± 7	40 652	317,0	R = 40 mm ± 2 mm
225	± 5	± 9	50 170	395,0	R = 7 mm ± 1 mm
280	± 6	± 11	76 662	615,0	R = 7,5 mm ± 1,5 mm

* Obliqueness = difference of diagonals of the square

Blooms of circular cross-section

Square side [mm]	Dimensional tolerance [mm]	Ovality [mm]	Cross-section area [sqmm]	Metrová hmotnosť [kg/m]
150	± 2	3	17 662	138,5
180	± 3	5	25 434	199,6
210	± 4	5	34 618	270,0
240	± 4	5	45 216	352,7
260	± 5	6	53 066	414,0
280	± 5	7	61 575	475,0

Lengths of steel blooms

Blooms and billets are available in lengths of 4 000 - 10 000 mm with length tolerance of + 50 mm. Straightness deviation is 1% of the length. Obliqueness of the front side is 5 °.

Marking of steel blooms

Each bloom is marked with heat number, steel grade code and stream number. The data is stamped or upon agreement written with non-washable paint on the front side of the bloom.

Laying of steel blooms

Square ones – in layers on the top of each other
Circular ones – on special wooden pads or tied with steel tape.