Importance of Electrolytic Chromium in the Metal Industry

Electrolytic chromium refers to the production of high purity chromium metal by selective anode dissolution and cathode deposition of crude chromium metal from fire metallurgy. Chromium metal and its compounds are widely used in chemical industry, refractory and metal materials. The addition of chromium to steel can change the properties of steel and improve the toughness of steel.

Basic Information of electrolytic chromium

CAS number: 7440-47-3

Molecular formula: Cr

Molecular weight: 51.99

Purity: ≥99.9%

EC No. : 231-157-5

Physical parameters of electrolytic chromium

Density :7.14g/mL(25℃)

Melting point :1857℃

Boiling point :2672℃

Applications of electrolytic chromium

Most of them are used to make stainless steel and other special steels, such as: auto parts, tools, tapes, videotapes, kitchen utensils such as kitchen knives. It can improve the strength of steel and has excellent heat resistance. Used in the manufacture of aircraft engines and nuclear power equipment for super alloy (super heat and corrosion resistant alloy) and coating applications. Chrome plating on the metal can prevent rust, also known as Korome, strong and beautiful. Chromium is also a major addition to stainless steel, providing corrosion protection properties. Chrome can be used to make pigments "chrome green" and "chrome yellow".

The difference between ordinary chromium particles and electrolytic chromium sheets

1. Chromium particles are irregularly granular and more three-dimensional; Electrolytic chromium sheets are very thin sheets prepared by deposition process

2. The purity is basically the same, 99.95. When encountering a good batch, the purity of electrolytic chromium sheet can reach 99.98, and the purity of electrolytic chromium sheet is better.

3 Application is not same, general chromium particles can be used for coating and smelting, electrolytic chromium plate is more used as raw material processing into other products, also used for melting additives

If coating is used, high purity chromium particles are recommended.

The role of chromium in metallic materials

1. Influence of chromium on steel structure

Chromium is a carbide forming element. In metal materials, it can form Cr3C and other metal compounds with carbon, and this metal compound has high strength, hardness. When it is distributed in granular dispersion on the metal matrix, it can greatly improve the strength, toughness and wear resistance of the material.

2. Chromium hinders austenite grain growth

All alloying elements except manganese can inhibit the growth of austenite grain during heating. In the material, the presence of Cr3C, an undissolved carbide formed with carbon, can inhibit the growth of austenite grains when heated at a low temperature. Thus, it is easy to obtain fine austenite grains and thus obtain fine cooled microstructure. We know that fine grains have higher strength, better plasticity and toughness than coarse grains.

3. Chromium can improve hardenability

The material is quenched in order to obtain more martensite structure. For alloys containing chromium, when quenched, chromium can make the C curve (austenite isothermal transition curve) shift to the right, and a double C curve appears. This reduces the minimum cooling rate for obtaining martensite tissue, which makes it easier to obtain martensite tissue and thus reduces the residual austenite content. In tempering, you can get more tempering tissue, and this kind of tempering tissue good performance is what we need.

4. Chromium can improve the tempering stability of steel

During tempering, chromium slows down the diffusion rate of iron and carbon atoms, so that the tempered steel martensite is not easy to decompose, and slow down the formation and aggregation of carbon. When tempered at the same temperature, the strength and hardness of alloy steel are higher than that of carbon steel with the same carbon content. On the contrary, when tempering into the same hardness, alloy steel because of high tempering temperature, long tempering time, and has higher plasticity, toughness, its internal stress is small.

5. The role of chromium in stainless steel

Chromium is the most basic alloy element in stainless steel, its content is generally more than 13%. Its main function is to improve the corrosion resistance of steel. In an oxidizing medium, the steel is protected by oxides that form a solid and dense layer of chromium on the surface. Chromium in steel can significantly improve the electrode potential of steel and reduce the electrochemical corrosion caused by different electrode potential. Chromium can also cooperate with nickel to form single-phase austenitic structure and give steel good corrosion resistance, toughness and strength.

Thus, the role of chromium in stainless steel is particularly important. To sum up, chromium plays an important role in metal materials. We fully realize this point, reasonable application of chromium in various materials can play a very good role in improving the performance of materials.