Chromium in high-temperature steel
The impact of chromium
The use of chromium in the composition of heat resisting steels greatly improves their resistance to oxidation. However, the effect of chromium is less effective than the influence of molybdenum, titanium and vanadium. Ferritic steels with the introduction of chrome improve qualities such as creep resistance, long-term strength, recrystallization temperature and the activation energy of self-diffusion. Also chrome on release of the deformed austenite, allows you to save distortion of its crystal lattice. The influence of chromium on high-temperature properties of ferritic steel depends on factors such as the level of chromium and other alloying elements, and not necessarily in equal proportions. In addition, the introduction of chrome changes the crystal lattice of the y-solid solution. In particular, increasing the energy of the atomic bonds in austenitic steels, improving high-temperature characteristics and temperature of recrystallization. Maximum heat resistance has been achieved with the introduction of the 15% chromium.
In the case of chromium hardening of austenitic steels occurs due to the formation of carbon-carbide-series, which are allocated in the y-solid solution during aging and hardening. However, the level of consolidation is reduced proportionally to the increase in operating temperature due to coagulation of carbides of chromium. This process occurs due to the low resistance of chromium carbides to heating. Therefore, the doping of chromium in austenitic steel is not the most efficient way to increase their heat resistance.
Additives chromium, you can also change the solubility of 'y-phase in complex alloys of Nickel, titanium and aluminum. Thus, dispersion hardening of these alloys. Moreover, the content of titanium in this process is minimal. However, this result is not always observed. So, in the case of using significant amounts of chromium to hire complexly alloyed heat-resistant steel, the formation of ferrite elements, which dramatically reduces high-temperature properties of the alloy.
To buy, price
In stock, LLC «Electrocentury-steel» always available high-quality stainless steel products at the best prices. All products are certified. A wide selection of products, comprehensive advice from our managers, reasonable prices and timely delivery define the face of our company. For wholesale orders flexible system of discounts.