B-40ACR

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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B-40ACr · Q/BQB 517-2023

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

Material category: Alloy steel
Subcategory: Cold-heading steel
Material form: Hot-rolled steel wire rod for cold heading
Original record status: Original standard verified
Standard edition: Q/BQB 517—2023
Table / clause: 6.1.1/Table 2, row 26, note a
PDF page references: 14
Unit: Mass fraction (wt%)
Analysis type: Heat analysis

Source document

Original composition-element notation and analysis basis

Al

Original element symbol: Alₜ
Symbol extracted from the original source: Alt
Original table column heading: Al t
Subscript in the original source: t
Subscript explanation: Only original table subscripts shall be retained; do not expand these into total aluminum or acid-soluble aluminum; Al without specified form shall not be directly equated
Standard edition: Q/BQB 517—2023
Table / clause: 2
Original table item number: 26
PDF page references: 14
Unit: Mass fraction (wt%)
Analysis type: Heat analysis
Original record status: Original column symbol verified
Original cell: ≥0.020

When the original analysis designations differ, or a record leaves them unspecified, comparability or a match cannot be concluded directly. Subscripts not explained by the source are not expanded here.

Carbon-equivalent reference

IIW / CEV：0.5600–0.7187Known-element contribution; incomplete value; missing V 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）：0.4450–0.5282Known-element contribution; incomplete value; missing 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：0.4750–0.5735 Independent-element envelope of standard ranges; not measured heat-analysis values 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.

Composition

Element	Composition requirement
C	0.4 ～ 0.44
Si	≤ 0.1 (lower limit not stated)
Mn	0.6 ～ 0.9
P	≤ 0.02 (lower limit not stated)
S	≤ 0.02 (lower limit not stated)
Cr	0.3 ～ 0.45
Alₜ	≥ 0.02 (upper limit not stated)
Ni	≤ 0.2 (lower limit not stated)
Cu	≤ 0.2 (lower limit not stated)
Mo	≤ 0.06 (lower limit not stated)

Applicability and limitations

Q/BQB 517—2023, official original on the Baosteel website, Table 2, row 26; cast-analysis mass fraction wt%. Table footnote a: residual Cr≤0.20, Ni≤0.20, Cu≤0.20, Mo≤0.06 wt%; where this row specifies otherwise, its requirement for that element takes precedence. Unlisted elements and special agreement requirements must not be treated as zero or assumed guarantees; permitted product-analysis deviations are governed separately by GB/T 222. Wire rod is delivered hot rolled; stricter P/S under Z1 and special surface or inclusion quality must be confirmed under normative Annex A and the contractual ordering codes. Fixed mechanical properties must not be inferred from the chemistry table.

Verification notes

All 104 rows of Table 1 and 34 rows of Table 2 in the original Q/BQB517:2023 from Baosteel’s official website were checked row by row; not mixed with older editions.