Designation
| Name |
The value |
| Designation GOST Cyrillic |
38ХГНМ |
| Designation GOST Latin |
38XGHM |
| Transliteration |
38HGNM |
| By chemical elements |
38CrMnНMo |
Description
38KHGNM steel is used: for the manufacture of products by cold extrusion and upsetting and hot-rolled (rolled, wire rod) for the manufacture and calibrated with special surface finish rolling and wire used for the manufacture of special fasteners, shafts, axles and other critical parts of the mining and metallurgical and oil-processing equipment, requirements of increased strength.
Standards
| Name |
Code |
Standards |
| Bars and shapes |
В32 |
GOST 10702-78, TU 14-1-1866-75 |
| Blanks. Of the workpiece. Slabs |
В31 |
TU 14-1-993-74 |
Chemical composition
| Standard |
C |
S |
P |
Mn |
Cr |
Si |
Ni |
Fe |
Mo |
| TU 14-1-993-74 |
0.37-0.43 |
≤0.035 |
≤0.035 |
0.7-1 |
0.4-0.6 |
0.17-0.37 |
0.4-0.7 |
Rest |
0.15-0.25 |
Fe is the basis.
According to TU 14-1-993-74 the chemical composition is given for steel grade 38ХГНМ. Permissible deviations from the norms for chemical composition: carbon ± 0.010%, manganese, chromium, molybdenum and silicon ± 0.020% each, nickel ± 0.030%, sulfur and phosphorus ± 0.0050% each.
Mechanical properties
| Section, mm |
σU, MPa |
y, % |
| Steel calibrated and calibrated with special surface finish after spheroidizing annealing |
|
≤690 |
≥60 |
Description mechanical marks
| Name |
Description |
| σU |
Limit short-term strength |
| y |
The relative narrowing |
Physical characteristics
| Temperature |
r, kg/m3 |
| 20 |
7800 |
A description of the physical symbols
| Name |
Description |
| Е |
The normal elasticity modulus |
| l |
Coefficient of thermal conductivity |
Technological properties
| Name |
The value |
| Weldability |
Difficult weldability. Method of welding: SMAW. Necessary preheating and subsequent heat treatment. |
| Склонность к отпускной хрупкости |
Inclined. |
| The temperature of forging |
The beginning of 1200 °C, the end of the 800°C. the cross Sections up to 250 mm are cooled in air, 251-350 mm - in the pit. |
| Flock-sensitive sensitivity |
Sensitive. |
| Macrostructure and pollution |
The macrostructure of the steel when checking on the etched transverse templeto should not have shrinkage looseness, blistering, delamination, cracks, inclusions and placenow. |
| Microstructure |
Harvesting on the other 14-1-993-74 should be supplied with a grain size not larger than 5 rooms, allowed the presence of small quantities of grains the 3. Depth bezoperatsionnogo layer in the workpiece (ferrite + transition zone) must not exceed 1.5% per side. |
