X12 steel
X12 steel
Steel X12: Handbook of steels and alloys. Below is systematized information on the purpose, chemical composition, types of supply, substitutes, critical point temperatures, physical, mechanical, technological and foundry properties for the grade — Steel X12.
General information on steel X12
| Kind of delivery |
| X12 strips, bars, including shaped: GOST 5950−73, GOST 2590−71, GOST 2591−71. Calibrated bar GOST 5950−73, GOST 7417−75, GOST 8559−75, GOST 8560−78. Grinded rod and silversilver GOST 5950−73, GOST 14955−77. Strip GOST 4405−75. Forged and forged blanks GOST 5950−74, GOST 1133−71, GOST 7831−78. |
| Application |
| Cold forgings of high resistance to abrasion, not subjected to strong shock and shocks; drawing boards, eyes for calibration of rod metal for thread rolling, bending and forming dies, complex sections of the body dies, stamping the active part of electric machines, etc. |
Chemical composition of steel X12
| Chemical element |
% |
| Vanadium (V), not more |
0.15 |
| Tungsten (W), not more |
0.20 |
| Silicon (Si) |
0.10−0.40 |
| Manganese (Mn) |
0.15−0.45 |
| Copper (Cu), not more |
0.30 |
| Molybdenum (Mo), max. |
0.20 |
| Nickel (Ni), not more than |
0.35 |
| Sulfur (S), not more than |
0.030 |
| Titanium (Ti), not more than |
0.03 |
| Carbon (C) |
2.00−2.20 |
| Phosphorous (P), not more than |
0.03 |
| Chromium (Cr) |
11.50−13.00 |
Process properties of steel X12
| Forging temperature |
| Beginning 1100, end 850. Slow cooling in the wells. |
Steel X12 critical point temperature
| Critical point |
°С |
| Ac1 |
810 |
| Ac3 |
835 |
| Ar3 |
770 |
| Ar1 |
755 |
| Mn |
180 |
Impact toughness of steel X12
Impact toughness, KCU, J/cm2
| Delivery condition, heat treatment |
KCU |
HRCe |
| Isothermal hardening at 1000 C with 40 min at 250−350 C. Tempering at 150 °C with one hour dwell time |
22 |
64 |
| Isothermal hardening at 1000 °C with 40 min at 250−350°C. Tempering at 200 °C with holding for 1 hour |
22 |
63 |
| Isothermal hardening at 1000 °C with an exposure time of 40 min at 250−350°C. Tempering at 250 °C with dwell time of 1 hour |
23 |
61 |
| 1050 °C isothermal hardening with 40 minutes holding time at 250−350°C. Tempering at 150 °C with dwell time of 1 hour |
32 |
62 |
| Isothermal hardening at 1050 °C with an exposure time of 40 min at 250−350°C. Tempering at 200 °C with dwell time of 1 hour |
33 |
60 |
| Isothermal hardening at 1050 °C with an exposure time of 40 min at 250−350°C. Tempering at 250 °C with holding for 1 hour |
34 |
58 |
| Tempering at 960−980°C in oil. Tempering at 200 °C with dwell time 1.5 h |
10 |
64 |
| Quenching at 960−980°C, oil. Tempering at 300 °C with dwell time 1.5 h |
15 |
62 |
| Quenching at 960−980°C, oil. Tempering at 400 °C with dwell time 1.5 h |
34 |
59 |
| Quenching at 960−980°C, oil. Tempering 500 C with holding for 1.5 h |
|
56 |
Steel hardness X12
| Delivery condition, heat treatment regime |
HRCe surface |
HB |
| Rings and strips annealed or high-temperatured |
|
255 |
| Samples. Hardened at 970 C, oil. Tempering 180 C. |
St. 62 |
|
| Isothermal annealing at 830−850°C, cooling at 40 deg/h to 720−740°C, holding for 3−4 h, cooling at 50 deg/h to 550 °C, air |
|
255 |
| Heating at 650−700 C. Hardening at 950−980°C, oil. Tempering at 180−200 C, 1.5h, air (final heat treatment |
61−63 |
|
| Tempering at 650−700°C. Hardening at 950−980°C, oil. Tempering at 320−350°C, 1.5h, air (final heat treatment mode. |
58−59 |
|
