DIN 1626 Welded Circular Unalloyed Steel Tubes Subject to Special Requirements | |||||||||
DIN 1629 Seamless Circular Unalloyed Steel Tubes Subject to Special Requirements | |||||||||
DIN 17175 Seamless Tubes of Heat-Resistant Steels | |||||||||
Steel Grade Symbol | Type of deoxidiz -ation |
Chemical Composition (cast analysis)
% (max unless otherwise specified) |
|||||||
C | Si (1) | Mn | P | S | N (2) | ||||
St 37.0 | R | 0.17 | - | - | 0.040 | 0.040 | 0.009(3) | ||
St 35.8 | - | 0.17 | 0.10-0.35 | 0.40-0.80 | 0.040 | 0.040 | - | ||
NOTES: | |||||||||
(1) The minimum Si content is allowed to fall below 0.10%, when the steel is aluminium-killed or vacuum-deoxidized. | |||||||||
(2) A content in excess of the maximum value stated is permitted if a P content less than the maximum specified by | |||||||||
0.005% P per 0.001% N is observed. However the N content shall not exceed a value of 0.012% in the cast analysis | |||||||||
and 0.014% in the product analysis. | |||||||||
(3) The specified value does not apply if the steels are supplied with the RR (instead of R) type of deoxidization. | |||||||||
R=killed, including semi-killed | |||||||||
RR= fully killed | |||||||||
Amounts by which the chemical composition in the product/sample analysis may deviate | |||||||||
from the limiting values applicable to the cast analysis. | |||||||||
Element | St 37.0 Allowable Deviation Amount % |
St 35.8 | |||||||
Upper Limits Quoted in Cast Analysis | Allowable Deviation Amount (2) % |
||||||||
C | 0.02 | 0.24 | \0.02 | ||||||
Si | - | 0.35 | \0.03 | ||||||
Mn | - | 1.00 | \0.04 | ||||||
P | 0.010 | 0.040 | \0.010 | ||||||
S | 0.010 | 0.040 | \0.010 | ||||||
N | 0.001(1) | - | - | ||||||
NOTES: | |||||||||
(1) A content in excess of the maximum value stated is permitted if a P content less than the maximum specified by | |||||||||
0.005% P per 0.001% N is observed. However the N content shall not exceed a value of 0.012% in the case analysis | |||||||||
and 0.014% in the product analysis (this does not apply to the RR type of deoxidization). | |||||||||
(2) In a cast the deviation of an element in a sample analysis is permitted to be below the minimum value or only | |||||||||
above the maximum value of the range stipulated for the cast analysis, though not both at the same time. | |||||||||
Steel Grade Symbol | Upper Yield Stress ReH | Tensile Strength Rm |
Elongation after | Impact | |||||
for Wall thicknesses, in mm | Fracture A5 | Strength | |||||||
ReH£16 | 16<ReH£40 | 40<ReH£60 | Longitudinal | Transverse | Transverse | ||||
Min N/mm2 | Min % | Min J | |||||||
St 37.0 | 235 | 225 | 215 | 350(1) -480 | 25 | 23 | - | ||
St 35.8 | 235 | 225 | 215 | 360-480 | 25 | 23 | 34 | ||
NOTE: | |||||||||
(1) For cold finished tubes in the NBK condition, minimum values of tensile strength lower than this value | |||||||||
by 10N/mm2 is permitted. | |||||||||