Sodium carboxymethyl cellulose (CMC) plays the following important roles in welding rods:
1. Binder: Sodium carboxymethyl cellulose has good bonding properties and can firmly bond the various components in the welding rod coating (such as arc stabilizers, slag forming agents, alloying agents, etc.) together, so that the coating can be closely attached to the surface of the welding core. This ensures that the coating will not fall off easily during the manufacturing, transportation and storage of the welding rod, maintains the integrity of the welding rod, and the coating can play a stable role during welding.
2. Slag formation and arc stabilization: During the welding process, sodium carboxymethyl cellulose will decompose at high temperatures and participate in the slag formation reaction, which helps to form a uniform and stable slag layer. A suitable slag layer can protect the welding pool and prevent harmful gases such as oxygen and nitrogen in the air from invading, thereby improving the quality of the weld. At the same time, it can also improve the stability of the arc, make the welding process smoother, reduce arc spatter, and improve the controllability and welding quality of the welding operation.
3. Improve the mechanical properties of the coating: It can increase the flexibility and plasticity of the coating, making it easier and more evenly attached to the welding core during the coating process, and the coating is not prone to cracking, falling off, and other problems during subsequent processing and use. In addition, the strength of the coating can be improved, making it less likely to be damaged when subjected to a certain external force.
4. Regulate the hygroscopicity of the coating: An appropriate amount of sodium carboxymethyl cellulose can regulate the hygroscopicity of the electrode coating to prevent the coating from affecting the welding performance due to excessive moisture absorption during storage. Appropriate hygroscopicity helps maintain the chemical stability of various components in the coating and prolong the storage life of the welding rod.
5. Fluxing effect: During the welding process, the substances produced by the decomposition of sodium carboxymethyl cellulose can reduce the melting point of certain components in the coating and promote the synthesis of the coating. It is an important intermediate for drugs such as berberine and baineting. In addition, some derivatives of salicylaldehyde also have biological activities, such as antioxidant, anti-inflammatory, and antibacterial, and have potential application value in drug research and development.
4. Electroplating: Salicylaldehyde is used as a nickel plating brightener in the electroplating industry. It can improve the brightness, leveling and corrosion resistance of the nickel-plated layer, making the coating more beautiful and durable. For example, adding an appropriate amount of salicylaldehyde and its derivatives to the nickel plating solution can improve the performance of the nickel plating process.
5. Organic synthesis: Salicylaldehyde, as an active organic compound, is an important intermediate in organic synthesis. It can react with a variety of compounds such as amines, alcohols, phenols, etc. to generate organic compounds with different structures and properties. For example, salicylaldehyde reacts with amino acids to generate Schiff base compounds, which have important applications in materials science, catalysis and other fields.
6. Fluorescent probe field: Salicylaldehyde and its derivatives can be used as fluorescent probes for detecting metal ions, biomolecules, etc. Because salicylaldehyde has special structure and optical properties, when it binds to a specific target molecule, it will cause changes in fluorescence properties, thereby achieving high sensitivity and high selectivity detection of the target molecule.
7. Analytical chemistry: Salicylaldehyde can be used for qualitative and quantitative analysis in analytical chemistry. For example, it can form complexes with certain metal ions with characteristic colors, which can be used for the identification and content determination of metal ions. At the same time, salicylaldehyde can also be used for the analysis and detection of certain organic compounds.
