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BMG-AT41™

Confused about the properties you should look for in Alloy T41 material? Not sure that it is the proper material for your or your customer’s needs? Are you being told that material offered from a new source will meet the exacting powergen end users’ requirements, but not sure of the exact specification they are offering?

Alloy T41’s use in critical applications means that material offered as meeting basic requirements without the extensive testing of such as our BMG-AT41™ could be an expensive mistake.

Below we provide our comparison between our BMG-AT41™ (based on our purchasing specification); the CEGB standard 02596 GDCD std 2 issue 2 & GEC/Alstom 30/227; Tata’s Durehete® 1055 (from Corus specification publication: “Durehete 1055” and mill cert (“Reported”); and the basic 1.7729 standard BS EN 10269:2013 / 1.7729.

If still in doubt, please ask our sales team for advice.

Requirements: BMG-AT41TM 02596 GDCD & 30/227 Durehete® 1055 BS EN 10269:2013 Steel No 1.7729
Spec BS EN 10269:1999
Steel No 1.7729
20CrMoVTiB4-10 plus additional testing
Standard 02596 GDCD Std 2 Issue 2 & GEC/Alstom 30/227 BS EN 10269:1999
Steel No 1.7729
20CrMoVTiB4-10
BS EN 10269:1999
Steel No 1.7729
20CrMoVTiB4-10
Chemistry Standard Chemistry with following exceptions:
Si Restricted for better properties 0.10-0.35
S Restricted for better properties 0-0.020
Sb Reported
R value “R parameter reported on BMG 3.1 certification
R value – calculated value. There is no mandated value in EN 10269, but generally it is deemed that R should be less than or equal to 0.1 (low R felt to have a beneficial effect on creep rupture ductility)
Conflict Materials Material not sourced as prime elements from conflict zones in accordance with the USA Dodd-Frank Act
Mill Location European mill with appropriate quality & testing approvals
Requirements: BMG-AT41TM 02596 GDCD & 30/227 Durehete® 1055 BS EN 10269:2013 Steel No 1.7729
Melting Ingot Cast Reported as Electric VDG Ingot The melting process for the starting material shall be at the discretion of the manufacturer.
Heat Treatment:
Step 1: Sub-critical anneal
As per 02596 GDCD & 30/227 After rolling and cooling to below 250 deg, 660-700 deg C / 3-5 hours, Cool to below 250 deg C 660-700o C / Air 660-700o C / Air, Water or Oil
Step 2: Harden As per 02596 GDCD & 30/227 970-990o C 970-990o C 970-990o C/ Air, Water or Oil
Quench: Ruling section
<= 35 mm: Oil
Oil Ruling section
<= 35 mm: Oil
Ruling section
>35mm<=50 mm:
Oil or Water
Oil or Water Ruling section
>35mm<=50 mm:
Oil or Water
Ruling section
> 50 mm: Water
Water Ruling section
> 50 mm: Water
Step 3: Temper As per 02596 GDCD & 30/227l 680-720o C for > 2 hours then Air Cool 680-720o C / Air 680-720o C
Extra Reported as Stress Relieve 660o C / Air
Furnace heating time Reported
Post Heat Treatment Material straightened and reeled / turned / polished as appropriate to produce a bright finish to BS EN 10002-1 Black Material finish
Hardness In accordance with CEGB STD 02596(2) 6.1:
100% of bars tested at one end and the centre, and results reported as min-max range.
Hardness limits 241-302 HB
>20% (minimum of 2) of bars from 1 heat treatment batch of same nominal size to be tested. Bars <= 150 mm dia: 2 tests – 1 on one end; 1 approx midway along length. Bars > 150 mm dia 2 tests: one from each end
Hardness limits 241-302 HB
Reported Brinell Hardness in accordance with EN ISO 6506-1.
No hardness limits given.
Requirements: BMG-AT41TM 02596 GDCD & 30/227 Durehete® 1055 BS EN 10269:2013 Steel No 1.7729
Tensile Tests As per 02596 GDCD & 30/227 Tests carried out on the hardest and softest bars found during hardness testing Reported EN ISO 6892-1 using test pieces from same cast and having been heat treated in the same batch and in same heat treatment facility .
UTS Restricted for better properties 820-1000 n/mm2 820-970 n/mm2 820-1000 n/mm2
0.2%PS As per 02596 GDCD & 30/227 660 n/mm2 min 660 n/mm2 min 660 n/mm2 min
Elongation As per 02596 GDCD & 30/227 15% min 15% min 15% min
Reduction of area 50% min 50% min 50% min
Impact testing Charpy according to EN 10045-1;
IZOD according to BS 131-1
IZOD & Charpy (average of 3 specimens) Tests carried out on the hardest and softest bars found during hardness testing
IZOD Tests carried out on the hardest and softest bars found during hardness testing IZOD to BS 131-1; (mean of 3 test pieces) EN ISO 148-1 at 20o C – longitudinal V-notch test pieces using a 2 mm striker. Result shall be mean of 3 tests. (one individual value may be lower than specified minimum by not less than 70% of value)
Impact limits: IZOD 27 J min 27 J min <= 100 mm 40 J min; > 100 mm 27 J min
Impact limits: Charpy <= 100 mm 40 J min; > 100 mm 27 J min <= 100 mm: 40 J min; > 100 -160 mm:
27 J min
UT 100% of bars tested to DIN EN 10308 03/02 (scanning coverage 1A, to Quality Class 4) Reported
(CES internal procedure)
The product shall be sound and free from defects that preclude their intended use
Crack Detection Bars <= 120 mm dia: 100% Circograph eddy current to BS EN ISO 15549 2010 using digital systems technology Bars >120 mm dia:
100% Magnetic Particle
Inspection tested to BS EN ISO 9934 2002 & BS EN ISO 9712 2002
Bars <= 150 mm dia: Crack detected by either Magnetic Particle Flaw Detection or eddy current method. Bars > 150 mm dia100% visual inspection Surface Inspection reported Slight surface imperfections are permitted. Visual examination only (without optical aids)
Composition check 100% PMI test on all bars 100% check
Grain Size Grain size restriction of ASTM E112 5 or finer Reported
Requirements: BMG-AT41TM 02596 GDCD & 30/227 Durehete® 1055 BS EN 10269:2013 Steel No 1.7729
Microstructure examination Tested conducted at an independent test house:
Examination of one longitudinal section across full cross-sectional width of bar;
Examined at not less than 100x magnification – if any coarse ‘prior to austenitic’ grain material is present such that the linear grain size exceeds 250 micron, the cast is rejected. The determined maximum single grain size is reported.
Certification Copy Mill cert and / or BMG ISO EN 10204 2004 compliant certification at purchaser’s request.
All certification shows product description, chemical analysis, mechanical properties, non-destructive tests, heat treatment details, grain size & microstructural examination details.
To requirements of BS 1506 plus details of heat treatment temperatures & times and any details of any reheat undertaken EN 10204 3.1 or 3.2
Identification symbol As per purchaser’s order:
Identified by hard stamp / etch and / or colour coded bar ends and / or labels at purchaser’s request
T41 Cast, batch, steel grade & origin of delivery.
Certification format All documentation sent in PDF format or hard copy at purchaser’s request. Documentation shall be capable of being microfilmed
Number of copies of certification At purchaser’s request 3 copies of certificate of test shall be supplied

 

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