ML30MN

3 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.

Open condition selection, comparison and carbon-equivalent tools for ML30MN →

ML30Mn · GB/T 5953

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

Material form: Wire rod
Original record status: Reference transcription of standard
Standard edition: GB/T 6478-2001
Table / clause: Table 3

Carbon-equivalent reference

IIW / CEV：0.3700–0.5567Known-element contribution; incomplete value; missing Mo, 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）：0.3000–0.4167Known-element contribution; incomplete value; missing 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：0.3300–0.4550Known-element contribution; incomplete value; missing Mo 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	0.27 ～ 0.34
Si	≤ 0.25 (lower limit not stated)
Mn	0.6 ～ 0.9
P	≤ 0.035 (lower limit not stated)
S	≤ 0.035 (lower limit not stated)
Ni	≤ 0.2 (lower limit not stated)
Cr	≤ 0.2 (lower limit not stated)
Cu	≤ 0.2 (lower limit not stated)

Applicability and limitations

Clause 6.1.1 of GB/T5953.1/.2:2009 follows the relevant standards identified in the contract; This is reference composition for the same designation under GB/T6478; the applicable standard must be confirmed by contract, and these values are not directly treated as mandatory composition under 5953. Historical data from an earlier edition. No edition is stated on the website; Displayed under this source edition; contract applicability is not established

Verification notes

Standard source: GB/T 6478-2001 · Table 3View associated products →

ML30Mn · GB/T 28906-2012

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

Subcategory: Cold-heading steel for quenching and tempering
Material form: Reference record
Original record status: Original standard verified
Standard edition: GB/T 28906-2012
Table / clause: Table 3; 6.1.5–6.1.7
PDF page references: 6、7

Carbon-equivalent reference

IIW / CEV：0.3800–0.5467Known-element contribution; incomplete value; missing Mo, 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）：0.3133–0.4067Known-element contribution; incomplete value; missing 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：0.3400–0.4450Known-element contribution; incomplete value; missing Mo 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	0.28 ～ 0.33
Si	0.1 ～ 0.25
Mn	0.6 ～ 0.9
P	≤ 0.025 (lower limit not stated)
S	≤ 0.025 (lower limit not stated)
Cr	≤ 0.2 (lower limit not stated)
Ni	≤ 0.2 (lower limit not stated)
Cu	≤ 0.2 (lower limit not stated)

Applicability and limitations

Table 3 Heat analysis, mass fraction %. ; 6.1.5 residual Cr/Ni/Cu are each ≤0.20%; Listed alloy Cr is not subject to residual Cr limits. ; 6.1.7 composition tolerances follow GB/T222; Do not treat heat analysis limits as product analysis tolerances. ; Table 3 of the 2012 edition does not have the optional aluminum and low silicon footnotes of the 2025 edition; new edition conditions shall not be applied. ; Clause 6.4.2: Steel types intended for quenching and tempering normally do not require mechanical-property testing.; If requested by the purchaser, agree the property values for the hot-rolled condition or heat-treated test specimens and state them in the contract; do not invent uniform guaranteed values..

Verification notes

Original PDF6, Table 3 and the PDF7 residual-content provisions were visually checked

ML30Mn · GB/T 6478-2001

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

Material form: Reference record
Original record status: Original standard verified
Standard edition: GB/T 6478-2001
Table / clause: Table 3 / 6.1.4–6.1.8
PDF page references: 5、6

Carbon-equivalent reference

Composition

Element	Composition requirement
C	0.27 ～ 0.34
Si	≤ 0.25 (lower limit not stated)
Mn	0.6 ～ 0.9
P	≤ 0.035 (lower limit not stated)
S	≤ 0.035 (lower limit not stated)
Ni	≤ 0.2 (lower limit not stated)
Cu	≤ 0.2 (lower limit not stated)
Cr	≤ 0.2 (lower limit not stated)

Applicability and limitations

GB/T6478-2001, Table 3, heat analysis wt%; 6.1.4 residual Cr/Ni/Cu are each ≤.20%; alloy Cr ranges are not subject to the residual maximum. ; 6.1.8 product-analysis tolerances require separate verification under GB/T222-1984, Table 2, and do not widen the default heat-analysis range. ; Actual 2001 edition; Composition from editions 2015 or 2025 is not substituted for this edition; specific dimensions and delivery mechanical properties require separate verification.

Verification notes

Visual check of four composition tables and clauses on pages 5 and 6 of the original PDF