SPHT3

1 source records. Standards, editions and conditions are presented separately; matching grade names do not establish interchangeability.

Refer to each source for mass fractions and analysis type. Missing values are not treated as 0. Manufacturer typical values, standard guarantees and measured heat results must remain separate. Use the material selector for calculations and condition selection.

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SPHT3 · Q/BQB 130-2003

Chemical composition source verified; this does not verify every standard clause, actual supply or measured heat results

Material category: Carbon steel
Subcategory: Slab steels
Material form: Rough-rolled slabs for rerolling
Original record status: Original standard verified
Standard edition: Q/BQB 130—2003
Table / clause: 4.1.1, Table 3 and notes 1–3
PDF page references: 3、4
Unit: Mass fraction (wt%)
Analysis type: Heat analysis

Source document

Carbon-equivalent reference

Estimates are presented separately for each applicable composition condition. Match the actual ordering conditions; ranges must not be combined.

G deoxidation method; applicable finished plate thickness 1.2–6 mm

IIW / CEV：0.2050–0.3783 Known-item contribution, not a complete value; missing Cr, Mo, V, Ni, Cu CEV = C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15; an engineering estimate of welding cold-cracking susceptibility for carbon and low-alloy steels.

Pcm（Ito–Bessyo）：0.1525–0.2758 Known-item contribution, not a complete value; missing Cu, Cr, Ni, Mo, V, B Pcm = C + Si/30 + (Mn + Cu + Cr)/20 + Ni/60 + Mo/15 + V/10 + 5B; mainly used for low-carbon low-alloy steels, particularly modern low-carbon pipeline steels; more relevant when C is approximately no higher than 0.11%.

CET：0.1750–0.3150 Known-item contribution, not a complete value; missing Mo, Cr, Cu, Ni CET = C + (Mn + Mo)/10 + (Cr + Cu)/20 + Ni/40; used in welding preheat assessment for ferritic steels, subject to the applicability conditions of EN 1011-2.

C capped steel (Table 3, note 2 b)); Applies to finished plate thickness 1.2–6 mm; Si≤0.05 wt%

Pcm（Ito–Bessyo）：0.1525–0.2692 Known-item contribution, not a complete value; missing Cu, Cr, Ni, Mo, V, B Pcm = C + Si/30 + (Mn + Cu + Cr)/20 + Ni/60 + Mo/15 + V/10 + 5B; mainly used for low-carbon low-alloy steels, particularly modern low-carbon pipeline steels; more relevant when C is approximately no higher than 0.11%.

Composition record (conditional branches apply; this is not an unconditional requirement)

Element	Composition requirement
C	0.13 ～ 0.22
Si	≤ 0.25 (lower limit not stated)
Mn	0.45 ～ 0.95
P	≤ 0.035 (lower limit not stated)
S	≤ 0.035 (lower limit not stated)

Applicability and limitations

Q/BQB 130—2003 is the standard for primary rolled slabs for re-rolling; The finished plate thickness in Table 3 refers to the thickness after the slab is re-rolled, not the slab thickness or wire diameter. Table 3 specifies heat analysis mass fraction wt%; C: capped steel; A: aluminum-killed steel; G: aluminum-silicon-killed steel; K: silicon-killed steel.. Must be read by condition row; elements not listed shall not be regarded as zero. Note 3 of Table 3 stipulates that slabs for thick plates (finished thickness ≥ 15 mm) shall use G aluminum-silicon killed steel; Table rows involving other deoxidation methods must have their applicability verified by both the supplier and the buyer. Product-analysis tolerances for killed steel are applied separately under GB/T 222; do not mix them with the heat-analysis values in Table 3.. Table 3, Note 2 permits the marked grades to be supplied as capped steel (C).; Al is not specified under condition a), and Si≤0.05 wt% under condition b); These have been listed separately as optional conditions.

Original condition-branch records

G deoxidation method; applicable finished plate thickness 1.2–6 mm

Element	Composition requirement
C	0.13 ～ 0.22
Si	≤ 0.25 (lower limit not stated)
Mn	0.45 ～ 0.95
P	≤ 0.035 (lower limit not stated)
S	≤ 0.035 (lower limit not stated)

Combined limits

PDF page references in the source

Source table row number

C capped steel (Table 3, note 2 b)); Applies to finished plate thickness 1.2–6 mm; Si≤0.05 wt%

Element	Composition requirement
C	0.13 ～ 0.22
Si	≤ 0.05 (lower limit not stated)
Mn	0.45 ～ 0.95
P	≤ 0.035 (lower limit not stated)
S	≤ 0.035 (lower limit not stated)

Combined limits

PDF page references in the source

Source table row number

A condition branch must be selected

Yes

Verification notes

Baosteel original Table 3, merged cells and notes checked row by row; select conditions by deoxidation method and finished-product thickness.