Scrapping standard for cast steel pulley of crane

Cast steel pulley is a kind of crane pulley. When the crane is working, steel wire rope is wound through the cast steel pulley, which plays a role of undertaking. It can change the tension direction of steel wire rope and save labor. Due to the working nature of the crane, the cast steel pulley is also an easily scrapped accessory. When it reaches the scrapping standard, it shall be replaced in time to prevent accidents and affect production.

Cast steel pulley

Casting is a kind of metal hot working technology that people master and use earlier. Casting is a method of casting liquid metal into a casting cavity suitable for the shape of the part and obtaining the part or blank after it is cooled and solidified. Most of the materials to be cast are solid but heated liquid metals (e.g. copper, iron, aluminum, tin, lead, etc.), and the materials of the mold can be sand, metal or even ceramics. The methods used will vary according to different requirements. Cast steel pulley is made of appropriate steel metal, melted and re cast, and then processed later. The casting production shall also comply with the specifications, otherwise the cast steel pulley will have cracks and other defects during production, resulting in scrapping.

الخردة القياسية من الفولاذ المصبوب بكرة

The scrapping standard of cast steel pulley is as follows:

1.  Cracks (repair welding is not allowed);
2.  Uneven wear of wheel groove up to 3mm;
3.  The wear of wheel groove wall thickness reaches 20% of the original size;
4.  The diameter at the bottom of the wheel groove is reduced by 50% of the diameter of the steel wire rope due to wear;
5.  Others that meet the scrapping conditions.
6.  Maintenance of pulley block, disassembly and cleaning of single beam bridge crane, maintenance of pulley block and inspection of cracks;
7.  Maintenance of pulley groove, inspection and assembly of shaft hole, pulley shaft shall not have cracks, journal shall not be worn, original diameter shall not be 30%, and taper shall not be greater than 5%. If it exceeds this value, it shall be replaced;
8. Check the groove shape of the pulley with a sample plate. The radial wear shall not exceed 30% of the wall thickness, otherwise it shall be scrapped. If it does not exceed the standard, it can be repaired. After overhaul, it shall be checked with a sample plate. The bottom and lateral clearance shall not be greater than 0.5mm, the deviation between the pulley groove line and the pulley line shall not be greater than 0.2mm, and the deviation between the rope groove and the contour end face shall not be greater than 1mm;
9.  After the overhaul of single beam bridge crane, the shaft hole is allowed to have defects of no more than 0.25 square centimeter, and the depth shall not exceed 4mm; After assembly, it shall be able to rotate flexibly by hand, and the lateral swing shall not exceed D / 1000. D is the nominal diameter of the pulley;
10.  Cast steel pulley will also be scrapped during production, resulting in defects such as pores, shrinkage cavities, sand holes, sand sticking and cracks. Casting defects have always been unavoidable and difficult to solve in the casting industry. The conventional method of repairing unqualified castings is mainly welding repair, which requires skilled workers, takes time and consumes a lot of materials. Sometimes, due to the influence of component materials, welding will also aggravate the damage and scrap the cast steel pulley.

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