What are the material maintenance methods of the chain of the guide rail elevator ? Sichuan Nanguang Machinery summarized the following points for everyone.
The guide rail type hydraulic lifter lifting chain is made of manganese 20Mn2 alloy structural steel. However, the 20Mn2 steel has a lower carbon content and a higher manganese content. During welding, the effect of manganese on the tendency to overheating is the strongest, causing grain growth and decarburization of the weld joint, forming a thick weld seam, and serious decarburization. Due to the coarse grains of the superheated structure, the controlled temperature range is small. If the low-carbon martensite treatment process is improper, it will easily cause the weld joint to be brittle. Therefore, the welding and heat treatment parameters are high, and the lifting chain is difficult to manufacture. Up to standard.
Lifting chain specifications generally include EN818 standard chain, 80-level American standard chain, T (8) level carburizing lifting chain, V (10) level lifting chain (blackened), T (8) level lifting chain (plating Zinc) and other specifications. The scrapping standards of lifting chains are mainly judged from the following aspects:
First, the allowable abrasion value of the lifting chain must not exceed 10% of the diameter of the circular chain bar material or the thickness of the assistive device.
Secondly, from the plane where the main ring is not bent, the main ring twisted more than 10 degrees should be scrapped.
Third, cracking, bending or twisting in any part of the chain and stuck or stiff blockage between the ring hinges cannot be ruled out.
Fourth, the permanent elongation of the lifting chain and the single ring must not exceed 5% of the original length.