Steel 18K
Description
Steel 18K
Steel 18K: a brand of steels and alloys. Below is a systematized information on the purpose, chemical composition, types of supplies, substitutes, temperature of critical points, physical, mechanical, technological and casting properties for the grade — Steel 18K.
General information of 18K steel
| Delivery type |
| Thick sheet GOST 5520−79, GOST 19903−74. |
| Application |
| For the manufacture of parts and parts of boilers, vessels operating under pressure at room, high and low temperatures. |
Chemical composition of 18K steel
| Chemical element |
% |
| Silicon (Si) |
0.17−0.37 |
| Manganese (Mn) |
0.55−0.85 |
| Copper (Cu), no more |
0.30 |
| Arsenic (As), no more |
0.08 |
| Nickel (Ni), no more |
0.30 |
| Sulfur (S), no more |
0.04 |
| Carbon (C) |
0.14−0.22 |
| Phosphorus (P), no more |
0.04 |
| Chromium (Cr), no more |
0.30 |
Mechanical properties of 18K steel
| Heat treatment, delivery condition |
Section, mm |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
KCU, J / m 2 |
| KCU — as delivered / after mechanical aging |
| Category sheets: 2−5, 10, 11, 16, 18 |
<20 |
275 |
430−520 |
20 |
59/29 |
| Category sheets: 2−5, 10, 11, 16, 18 |
21−40 |
265 |
430−520 |
20 |
59/29 |
| Category sheets: 2−5, 10, 11, 16, 18 |
41−60 |
255 |
430−520 |
20 |
59/29 |
Mechanical properties when tested for long-term strength
| Creep limit, MPa |
Creep rate,% / h |
t test, ° С |
Long-term strength, MPa |
Duration tests, h |
t test, h |
| 162 |
1/10000 |
400 |
115 |
10000 |
450 |
| 64 |
1/10000 |
480 |
69 |
100,000 |
450 |
| 108 |
1/100000 |
400 |
68 |
200,000 |
450 |
| 31 |
1/100000 |
480 |
33 |
200,000 |
480 |
Technological properties of steel 18K
| Weldability |
| Can be welded without restrictions. |
Yield strength of steel 18K
| Test temperature, ° C / s 0.2 |
| 200 |
250 |
300 |
350 |
400 |
450 |
| 225 |
205 |
175 |
155 |
135 |
120 |
