Hardness range of steel pipe used in thermal power plants

2021-11-12
Hardness range of steel (steel pipe) used in thermal power plants
 
 
The steel used in thermal power plants is mainly used in the four major pipelines of thermal power plants.
 
The four major pipelines of a thermal power plant include: a main steam pipeline, a high temperature reheat steam pipeline, a low temperature reheat steam pipeline, and a high pressure water supply pipeline.
Therefore, the steel (steel pipe) commonly used in thermal power plants must meet the requirements for the use of the four major pipelines.


Commonly used steel (steel pipe) material for thermal power plants:
SA210 C, SA234-WPC, SA234-WPB, 20MnMo, 15MnMoV, SA209 T1, SA182 F1, SA234-WP111, SA234-WP121, A691-11 / 4Cr, SA213-T2, SA182-F2, SA182-F12, A213 T11, A213 T12, A213 T23, SA182-F22, 1Cr5Mo, A213 T91, A213 T92,1Crl3, OCrl3A1,1Crl8Ni9,0Cr23Ni13, 0Cr23Ni13, l0, 20, 12Cr2Mo, 10CrMoV, 15CrMo, 15CrMo, ZGZOCrMoV, ZG15Cr1Mo1V, 12Cr1MoV, Cr2Mo1, SA213 T9 , 10CrMo9lO and so on.



Hardness power plant common steel hardness range chart


Steel   Grade Hardnes Standard
Steel pipe used in thermal power plants 1 SA210C HB≤179 ASTM A210
2 SA234-WPC HB≤197 ASTM A234
3 SA234-WPB HB≤197 ASTM A234
4 20MnMo HB149~217 JB755
5 15MnMoV HB156~228 JB755
6 SA209T1 HB≤146 ASTM A209
7 SA182F1  HB143~192 ASTM A182
8 SA234-WP111 HB≤197 ASTM A234
9 SA234-WP121 HB≤197 ASTM A234
l0 T1  HB≤146 ASTM A209
11 A691-11/4Cr HB≤201 ASTM A691
l2 SA213-T2  HB≤217 ASTM A213
l3 SA182-F2  HB143~192 ASTM A182
l4 SA182-F12 HB 121~174 ASTM A182
l5 T11 HB≤163 ASTM A213
l6 T12 HB≤163 ASTM A213
l7 T23 HB≤220 ASTM A213
l8 SA182-F22 HB≤170 ASTM A182
l9 1Cr5Mo HB 156~241 JB755
2O T9l HB≤250 ASTM A213 
2l T92 HB≤250 ASTM A213 
22 1Crl3 HB≤159 GB 1220
23 OCrl3A1 HB≤183 GB 1220
24 1Crl8Ni9 HB≤187 GB 1220
25 0Cr23Ni13 HB≤187 GB 1220
26 1Cr18Ni9Ti HB≤187 GB 1220
27 l0 HB≤137 GB3087
28 20 HB≤156 GB3087
29 12Cr2Mo HB≤170 GB5310
30 10CrMoV HB≤166 GB5310
3l 15CrMo  HB≤179 GB5310
32 ZG20CrMo HB 135~140 DJ156
33 ZGZOCrMoV HB135~140 JB264O
34 ZG15Cr1Mo1V HB2OO~255 JB264O
Straight,
Bent pipe,
Steam guide
1 12Cr1MoV HB≤170  
2 Cr2Mo1  HB≤170  
3 SA213:T9 HB≤179  
4 SA213: other HB≤163  
Alloy steel header 1 12Cr1MoV HB≤170  
2 10CrMo9lO HB≤170  
Weld
The weld of the same kind of steel welded joints is generally not more than 100 times of the base material HB after heat treatment;
For non-austenitic welds of welded joints in heterogeneous port, the hardness after heat treatment generally does not exceed the height of high alloy steel base material HB plus 100; both must meet the following requirements:
l Total alloy content <3% HB≤270
The same kind of steel:
DL/T 869-2012
Dissimilar steel:
DL/T 752-2010
2 Total alloy content  3%~10% HB≤300
3 Total alloy content >10% HB≤350
Note: Dissimilar steel calculates the total alloy content from the composition of the base material with low alloy content.
Turbine rotor l 25Cr2Ni4MoV HB230~260
(236~286)
 
2 34CrNi3Mo HB240~270  
3 30Cr2MoV(P2) HB255~321
(241~277)
 
4 30Cr1Mo1V HB250~280 JB/T 1265
High temperature bolt l 35 HB146~187 DL439-91
2 45 HB187~227
3 20CrMo HB197~241
4 35CrMo HB217~255
5 20Cr1MolV1  HB248~277
6 20Cr1MolVTiB  HB255~293
7 25Cr2Mo1V HB241~277
HB240~290 DL438-2009
8 25Cr2MoV HB241~277 DL439-91
HB240~290  
9 C422(20Cr12NiMoWV) HB277~331  
l0 R26(Ni-Cr-Co alloy) HB262~331  
11 20Cr1Mo1VNbTiB HB241~285 DL439-91
HB240~290 DL438-2009 
l2 W4OCrMoV HB255~321  
13 42CrMo HB248~311
l4 K11C81E-R0(High alloy steel) HB291~321 DL438-2009
15 GH4145/SQ(alloy) HB262~331
Steam turbine bolt 1 30CrMoA Rm(σb)≥686Mpa HB217~255 Steam turbine 
Rm(σb)≥784Mpa HB241~277
Rm(σb)≥862Mpa HB277~302
2 30Cr2MoV Rm(σb)≥735Mpa HB241~277
Rm(σb)≥833Mpa HB269~302
Note: The nut material is generally one level lower than the bolt material, and the hardness is 20~50HB.


Detailed explanation:
T91 190~250
T22 130~179
 
 
Standard GB3077-88
The hardness of 12Cr1MoV steel is not more than 179 in the annealing or high temperature tempering supply state.
The hardness range of 25Cr2Mo1V as steel for bolts is: HB241--277
35 steel The hardness range of steel used as bolts is: HB146--187
20Cr1Mo1VTiB as a bolt steel hardness range: HB255--293
 
 
Standard GB699-88
20 steel delivery state hardness HB is not greater than 156
30 steel delivery state hardness HB is not more than 170
35 steel delivery state hardness HB is not greater than 179


Common bolt material hardness standards

Grade Hardness Note
K11C81E-Ro HB291~HB321 High alloy steel
GH4145/SQ HB262~HB331 Alloy steel
C-422(20Cr12NiMoWV) HB277~HB331 High alloy steel
R26(Ni-Cr-Co) HB262~HB331 Alloy steel


New bolts of 20Cr1Mo1VNbTiB steel after quenching and tempering, hardness is HB240~HB290;
After the operation of the 25Cr2Mo1V and 25Cr2MoV steel bolts, the test results should be in accordance with the hardness of HB240 ~ HB290;


Standard SA234 (forged carbon steel and alloy steel pipe fittings for medium and high temperature)
 
For WP5, WP9 and WPR grade steel pipe fittings - up to 217HB.
For WP91 grade steel pipe fittings - up to 248HB.
For other grades of steel fittings - up to 197HB.
 
 
Standard SA213 (seamless ferrite and austenitic alloy tubes for boilers, superheaters and heat exchangers T)
 
The hardness of T5b, T7 and T9 grade steel shall not exceed 179HB/190HV (89HRB), the hardness of T91 and T92 grade steel shall not exceed 250HB/265HV (25HRC), and the hardness of 18Cr-20Mo grade steel shall not exceed 217HB/230HV ( 96HRB),
 
All other ferrite grade hardnesses should not exceed 163HB/170HV (85HRB).
The hardness of TP201 and TP202 grade steel should not exceed 219HB/230HV (95HRB).
Tubes made from S30815, S31272, S31050 and S25700 have a Brinell hardness of no more than 217 HB (95 HRB).
 
The Brinell hardness of pipes made of TP310HCbN grade steel shall not exceed 256 HB (100 HRB).
The hardness of XM-19 (UNS S20910) grade steel should not exceed 250HB/265HV (25HRC).
The hardness of all other austenitic grade steels shall not exceed 192HB/200HV (90HRB).
 
 
 
Standard SA210 (seamless medium carbon steel tube for boiler and overheating T)
The hardness of the A-1 grade pipe shall not exceed the Rockwell hardness of 79 HRB or the Brinell hardness of 143 HB.
The hardness of the Class C pipe shall not exceed 89 Rockwell hardness or 179 HBB hardness.
 
 
Other:
10CrMo910 corresponds to China's grade 10Cr2Mo1. The US grade is SA213T22 (ASTM). According to DIN EN 10028-1/2, 10CrMo910 and P22 have a hardness range of 130-175HB.
Soviet grades 22K and 20K correspond to Chinese grades 22g and 20g; US grades are SA414E and SA414D
 
 
Weld hardness standard:
The weld hardness of the same kind of steel welded joint after heat treatment generally does not exceed the Brinell hardness of the base metal plus 100HBW, and does not exceed the following provisions:
When the total content of the alloy is <3%, the Brinell hardness value is ≤270HBW
When the total content of the alloy is 3%-10%, the Brinell hardness value is ≤300HBW
When the total content of the alloy is >10%, the Brinell hardness value is ≤350HBW
Weld hardness test of dissimilar steel welded joints shall comply with the provisions of DL/T752.
The hardness of the heat-resistant alloy steel weld is not lower than the hardness of the base metal.
 
 
 
Weld metallographic organization standards:
1, no cracks;
2. There is no burnt tissue;
3. There is no hardened martensite structure.
 
 
 
Specification for welding process qualification of boiler and pressure vessel in thermal power plants (SD340-89)
 
The hardness of the weld and heat affected zone generally does not exceed the Brinell hardness of the parent metal plus 100
Steel with chromium content <2%, HB≤250
Steel with chromium content ≥2%, HB≤300
Metal fusion welding weld defect classification and description GB6417-86
Metal fusion weld weld defects are classified into six categories: cracks, holes, solid inclusions, unfused and incomplete, and shape defects.
Unfused is divided into: the side wall is not fused, the layers are not fused, and the root of the weld is not fused.

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