Steel grades to classify various steels by their composition and physical properties have been developed by a number of standards organizations.

Steel grades standards by countryEdit

Note that an increasing number of national European standards (DIN, AFNOR, UNE, UNI, etc.) and UK standards are being withdrawn and replaced by European Standards (EN). This task is carried out by the Comité Européen de Normalisation (CEN) (European Committee for Standardization).

European standard steel gradesEdit

 
EN 10027-1 steel grade designation system.

European standard steel grade names fall into two categories:[1]

  1. Steel specified by purpose of use and mechanical properties.
  2. Steel specified by chemical composition.

The inclusion of a letter 'G' before the code indicates the steel is specified in the form of a casting.

Category 1Edit

Basic grade designations for category 1 steels consist of a single letter (designating application) then a number signifying the mechanical property (often yield strength) dictated in the standard for that application designation. For some application designations another letter is included before the property value, this number is used to indicate any special requirements or conditions. These additional letters and values depend entirely on the application of the steel and are specified in the standard and far too numerous to mention here.

The next set of 3 digits gives the steel's minimum yield strength. So S355 has a minimum yield strength of 355 MPa for the smallest thickness range covered by the relevant standard – i.e. EN10025.[2]

Below is a table indicating the most common application codes.

Application symbol Meaning Mechanical Property Details
S Structural steel Minimum Yield Strength
P Steel for pressure lines and vessels Minimum Yield Strength
L Steel for pipe and tube Minimum Yield Strength
E Engineering steels Minimum Yield Strength
B Steel for reinforced concrete Characteristic Yield Case
R Steel for rail use Minimum Yield Case
H High Tensile Strength Flat products Minimum Yield Case If followed by T then the given mechanical property is minimum tensile strength
D Flat Products for Cold Forming Followed by C, D or X and two numbers characterising steel
T Tinmill Products Nominal Yield Case
M Electrical Steel Number = 100 × specific loss in W/kg

Number = 100 × nom thick in mm

Letter for type of product (A, K, P or S[3])

Additional symbolsEdit

In addition to the above category codes there are symbols that can be added to the grade code to identify any additional compositional requirements, delivery conditions, mechanical properties, &c. These values depend solely on the type/application code given in the first part of the code and are so numerous as to be impossible to indicate here. Additional symbols are separated from the main code by the plus sign (+).

The most common additional symbols are the impact and temperature codes for structural steels, category 1 - Sxxx.

Impact Resistance Temperature
Impact
code
Testing
strength
Temperature
code
Testing
temperature
J 27 J R Room temperature
K 40 J O 0 °C
L 60 J 2 -20 °C
3 -30 °C
4 -40 °C
5 -50 °C
6 -60 °C

Delivery condition codes are also relatively common, the most common being:

Code Condition
A Annealed
QT Quenched and tempered
N Normalised
SR Stress relieved
C Cold worked
U Untreated

Electrical steel type of product letters (bold are most recent version 2016):

Code Maximum specific loss

expressed for magnetic induction

Type of product
A 1.5T @50Hz non oriented
D (formerly B) " non-alloy semi-finished (not finally annealed)
E " alloy semi-finished (not finally annealed)
K (=D+E) " non-alloy and alloy electrical steel sheet/strip in the semi-processed state
N " for normal grain oriented products
P 1.7T @50Hz high permeability grain oriented
S " conventional grain oriented

European standard steel numberEdit

In addition to the descriptive steel grade naming system indicated above, within EN 10027-2 is defined a system for creating unique steel grade numbers. While less descriptive and intuitive than the grand names they are easier to tabulate and use in data processing applications.

The number is in the following format: x.yyzz(zz)
Where x is the material type (only 1 is specified so far), yy is the steel group number (specified in EN10027-2) and zz(zz) is a sequential number designated by the certifying body, the number in brackets being unused but reserved for later use.

The steel groups are indicated below:

Code Type
Non-alloy steels
00 & 90 Basic steels
0x & 9x Quality steels
1x Special steels
Alloy steels
2x Tool steels
3x Miscellaneous steels
4x Stainless and heat resistant steels
5x – 8x Structural, pressure vessel and engineering steels
08 & 98 Special physical properties
09 & 99 Other purpose steels

The current certification body is the VDEh in Düsseldorf, Germany.

ComparisonsEdit

Below is a table comparing steel grades from different grading systems.

Comparison of steel grades by chemistry[4][5]
EN steel number
(Europe)
EN steel name
(Europe)
ASTM grade
(USA)
AISI/SAE grade
(USA)
UNS
(USA)
DIN
(Germany)
BS
(UK)
UNI
(Italy)
JIS
(Japan)
Carbon steels
1.1141
1.0401
1.0453
C15D
C18D
1010
1018
CK15
C15
C16.8
040A15
080M15
080A15
EN3B
C15
C16
1C15
S12C
S15
S15CK
S15C
1.0503
1.1191
1.1193
1.1194
C45 1045 C45
CK45
CF45
CQ45
060A47
080A46
080M46
C45
1C45
C46
C43
S45C
S48C
1.0726
1.0727
35S20
45S20
1140/1146 35S20
45S20
212M40
En8M
1.0715
1.0736
11SMn37 1215 9SMn28
9SMn36
230M07
En1A
CF9SMn28
CF9SMn36
SUM 25
SUM 22
1.0718
1.0737
11SMnPb30
11SMnPb37
12L14 9SMnPb28
9SMnPb36
230M07 Leaded
En1B Leaded
CF9SMnPb29
CF9SMnPb36
SUM 22
SUM 23
SUM 24
Alloy steels
1.7218 4130 25CrMo4
GS-25CrMo4
708A30
CDS110
25CrMo4 (KB)
30CrMo4
SCM 420
SCM 430
SCCrM1
1.7223
1.7225
1.7227
1.3563
42CrMo4 4140/4142 41CrMo4
42CrMo4
42CrMoS4
43CrMo4
708M40
708A42
709M40
En19
En19C
41CrMo4
38CrMo4 (KB)
G40 CrMo4
42CrMo4
SCM 440
SCM 440H
SNB 7
SCM 4M
SCM 4
1.6582
1.6562
34CrNiMo6 4340 34CrNiMo6
40NiCrMo8-4
817M40
En24
35NiCrMo6 (KB)
40NiCrMo7 (KB)
SNCM 447
SNB24-1-5
1.6543
1.6523
20NiCrMo2-2 8620 21NiCrMo22
21NiCrMo2
805A20
805M20
20NiCrMo2 SNCM 200 (H)
1.5415 16Mo3 A240 A/B/C K12822
K12320
K12020
K11820
15Mo3 1503-243B
240
243
15Mo3
16Mo3
STBA12
Stainless steels
1.4310 X10CrNi18-8 301 S30100
1.4318 X2CrNiN18-7 301LN
1.4305 X8CrNiS18-9 303 S30300 X10CrNiS18-9 303S 31
En58M
X10CrNiS18-09 SUS 303
1.4301 X2CrNi19-11
X2CrNi18-10
304 S30400 X5CrNi18-9
X5CrNi18-10
XCrNi19-9
304S 15
304S 16
304S 18
304S 25
En58E
X5CrNi18-10 SUS 304
SUS 304-CSP
1.4306 X2CrNi19-11 304L S30403 304S 11 SUS304L
1.4311 X2CrNiN18-10 304LN S30453
1.4948[citation needed] X6CrNi18-11 304H S30409
1.4303[citation needed] X5CrNi18-12 305 S30500
1.4401
1.4436
X5CrNiMo17-12-2
X5CrNiMo18-14-3
316 S31600 X5CrNiMo17 12 2
X5CrNiMo17 13 3
X5CrNiMo 19 11
X5CrNiMo 18 11
316S 29
316S 31
316S 33
En58J
X5CrNiMo17 12
X5CrNiMo17 13
X8CrNiMo17 13
SUS 316
SUS316TP
1.4404 X2CrNiMo17-12-2 316L S31603 316S 11 SUS316L
1.4406
1.4429
X2CrNiMoN17-12-2
X2CrNiMoN17-13-3
316LN S31653
1.4571 316Ti S31635 X6CrNiMoTi17-12 320S 33
1.4438 X2CrNiMo18-15-4 317L S31703
1.4541 321 S32100 X6CrNiTi18-10 321S 31 SUS321
1.4848 GX40CrNiSi25-20 A351 HK40 J94204 SEW 595 GX40CrNiSi25-20 310C40 SCH22
1.4859 GX10NiCrSiNb32-20 N08151 GX10NiCrSiNb32-20
1.4878,[citation needed] X12CrNiTi18-9
X8CrNiTi18-10
321H S32109
1.4906 X7CrNiNb18-10 347H S34709
1.4512[citation needed] X6CrTi12 409 S40900 SUH409
410 S41000
1.4016 430 S43000 X6Cr17 430S 17 SUS430
440A S44002
1.4112[citation needed] 440B S44003
1.4125[citation needed] 440C S44004 X105CrMo17 SUS440C
1.4104 430F S44020 X14CrMoS17 SUS430F
1.4057 X17CrNi16-2 431 X[6] S43100 X16CrNi16 431S 29 SUS431
1.5423 16Mo5 A335 P1 4520
4419H
4419
K11522 16Mo5 STPA12
1.7715 14MoV6-3 A335 P2 K11547 14MoV6-3 660 STPA20
1.7335
1.7338
13CrMo4-5
10CrMo5-5
A335 P11 K11597 STPA23
1.7375
1.7380
1.7383
10CrMo9-10
11CrMo9-10
12CrMo9-10
A335 P22 K21590 17175 10CrMo910 STPA24
1.7362
1.7366
X11CrMo5
X12CrMo5
12CrMo19-5
A335 P5 501
502
K41545
S50100
S50200
STPA25
1.7386 X11CrMo9-1
X12CrMo9-1
A335 P9 503 S50400
S50488
K90941
STPA26
1.4903 X10CrMoVNbN9-1 A335 P91 K91560 X10CrMoVNbN9-1
1.4905
1.4906
X11CrMoWVNb9-1-1
X12CrMoWVNbN10-1-1
A335 P92 K92460 X11CrMoWVNb9-1-1
X12CrMoWVNbN10-1-1
1.4539 X1NiCrMoCu25-20-5 904L N08904
1.4547 X1CrNiMoCuN20-18-7 S31254
1.4565 NIT50 S20910
NIT60 S21800
Tool steels
1.2363 X100CrMoV5 A-2 T30102[7] X100CrMoV51 BA 2 X100CrMoV5-1 KU SKD 12
A-3 T30103[8]
A-4 T30104[9]
A-6 T30106[10]
A-7 T30107[11]
A-8 T30108[12]
A-9 T30109[13]
1.2365 X32CrMoV3-3
32CrMoV12-28
H10 T20810 X32CrMoV3-3
32CrMoV12-28
SKD 7
1.2379 X153CrMoV12 D-2 X153CrMoV12-1 BD 2 X155CrVMo12-1 SKD 11
1.2510 O-1 100MnCrW4 Bo 1 95MnWCr-5 KU

American Petroleum Institute (API) steel gradesEdit

Color codingEdit

In order to clearly distinguish the steel grade, tubing, casing and its coupling should be painted with color codes respectively. Color bands should be painted on tubing and casing body longer than 600mm to either end. The whole outer-body of the coupling needs to be painted color and then color codes

Steel Grade Coupling Tubular Body
API Tubing and Casing H40 None None or black band at the manufacturer's option
J55 all green. one green band
K55 all green two green bands
N80-1 all red one red band
N80-Q all red + one green band one red band + one green band
L80-1 all red + one brown band one red band + one brown band
L80-9Cr colorless + two yellow bands one red band + one brown band + two yellow bands
L80-13Cr colorless + one yellow band one red band + one brown band + one yellow band
C90-1 all purple one purple band
T95-1 all silver one silver band
C110 all white + two brown bands one white band + two brown bands
P110 all white one white band
Q125 all orange one orange band

API 5B and 5CT provide various steel grades and color codes of each grade, offering detailed and overall information of casing and tubing, which help you clearly pick out the most suitable products for different well application.

ReferencesEdit

NotesEdit

  1. ^ EN 10027, European committee for standardisation
  2. ^ "EN 10027 Steel Names and their Meaning".
  3. ^ https://www.3ppars.com/WebsiteImages/download/48771479212.PDF
  4. ^ "Standards comparison". Retrieved 2008-12-31..
  5. ^ Oberg, pp. 411-412.
  6. ^ "Chronifer M-15 X (431 X) steel developed by L. Klein SA". www.kleinmetals.ch. Retrieved 2017-01-12.
  7. ^ AISI A2, Efunda, archived from the original on 2010-12-25, retrieved 2010-12-25.
  8. ^ AISI A3, Efunda, archived from the original on 2010-12-25, retrieved 2010-12-25.
  9. ^ AISI A4, Efunda, archived from the original on 2010-12-25, retrieved 2010-12-25.
  10. ^ AISI A6, Efunda, archived from the original on 2010-12-25, retrieved 2010-12-25.
  11. ^ AISI A7, Efunda, archived from the original on 2010-12-25, retrieved 2010-12-25.
  12. ^ AISI A8, Efunda, archived from the original on 2010-12-25, retrieved 2010-12-25.
  13. ^ AISI A9, Efunda, archived from the original on 2010-12-25, retrieved 2010-12-25.

BibliographyEdit

  • Oberg, E.; et al. (1996), Machinery's Handbook (25th ed.), Industrial Press Inc

External linksEdit