Designation
| Name |
The value |
| Designation GOST Cyrillic |
07Х20Н25М3Д2ТЛ |
| Designation GOST Latin |
07X20H25M3D2TL |
| Transliteration |
07H20N25M3D2TL |
| By chemical elements |
07Cr20Н25Mo3Cu2Ti |
Description
07Х20Н25М3Д2ТЛ steel is used: for the manufacture of the 1st, 2nd and 3rd groups casting parts of valves and actuators to it operating in sulphuric and phosphoric acids of various concentrations at temperatures up to +80 °C, and in less aggressive environments when the working environment temperature from -70 to +300 °C without limitation of the rated working pressure.
Note
Casting parts of pipe fittings of steel 07Х20Н25М3Д2ТЛ demanding resistance to corrosion cracking are subjected to stabilization annealing step (Mode 2).
Standards
| Name |
Code |
Standards |
| Steel castings |
В82 |
OST 26-07-402-83, ST ЦКБА 014-2004 |
| Welding and cutting metals. Soldering, riveting |
В05 |
RD РТМ 26-07-233-79 |
Chemical composition
| Standard |
C |
S |
P |
Mn |
Cr |
Si |
Ni |
Fe |
Cu |
Ti |
Mo |
| ST ЦКБА 014-2004 |
≤0.07 |
≤0.02 |
≤0.03 |
≤0.8 |
19-21 |
≤0.8 |
24-26 |
Rest |
1.8-2.2 |
0.4-0.7 |
2.3-3 |
Fe is the basis.
Mechanical properties
| sT|s0,2, MPa |
σU, MPa |
d |
y, % |
KCU, kJ/m2 |
| Casting parts of pipe fittings. Mode 1: Quenching in water from 1100-1150 °C or Mode 2: Annealing at 1100-1120 °C (exposure 1.5 h), cooling with the furnace to 950 °C (exposure 2 hours), cooled with the furnace to 300 °C, air cooling |
| ≥200 |
≥400 |
≥20 |
≥20 |
≥800 |
Description mechanical marks
| Name |
Description |
| sT|s0,2 |
Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2% |
| σU |
Limit short-term strength |
| d |
Elongation after rupture |
| y |
The relative narrowing |
| KCU |
Toughness |
Technological properties
| Name |
The value |
| Surfacing |
For the argon arc and TIG welding of sealing and friction surfaces of parts of pipeline fittings are used electrodes and welding rods of alloy 06Х20Н10М3Д3С4Л po RD RTM 26-07-233-79. Before welding the parts must be subjected to preliminary heating in a furnace at a temperature of from +400 to +650 °C. To enhance the corrosion resistance of weld metal and relieve internal stresses after welding should be heat treatment of parts in the following mode: fit into the oven at temperatures up to +500 °C, heating from +950 to +1050 °C, exposure - 1.5 to 2 hours, cooling with the furnace. |
