Steel Scrap Grab Bucket

1. Working environment :

 If there are corrosive substances in the working environment of the grab, stainless steel, titanium alloy, and other corrosion-resistant materials should be selected.

 If the grab is used in high-temperature conditions, such as heat treatment, aluminum plants, chemical plants, and other high-temperature places, heat-resistant steel such as ZG35Cr25Ni20Si2 can be used.

 In mines, gravel quarries, and other abrasive environments, it is appropriate to use high-manganese steel, tungsten carbide, and other wear-resistant materials.

2. Steel scrap grabs that need to grip heavy materials such as steel slag with high strength, good wear resistance, and impact resistance should be selected, such as high manganese steel, tungsten carbide, high strength alloy steel, etc.

3. With a limited budget, consider using low-cost steel with relatively weak properties, i.e. plain carbon steel; in the case of budget-adequate and long-term interests, high-performance materials such as high-strength steel, tungsten carbide, titanium alloy, etc., which are relatively expensive but with high performance and low frequency of replacement and maintenance, can be considered.

Advanced finite element analysis (FEA) software is used to calculate the structural strength and stiffness, optimize the overall structure of the grab, and ensure that the stresses in the key parts of the grab are evenly distributed under various working conditions.

The design of the bucket body should fully consider the fluidity and accumulation characteristics of the material, and adopt a suitable curve shape and internal reinforcement arrangement to reduce the material residue and improve the gripping efficiency.

When cutting the selected raw material, the mechanic should follow the final confirmed drawing between the design team and the customer. And keep communication and feedback with engineers.

For the parts to be welded, an advanced welding process, such as gas-shielded welding (GMAW/MIG or GTAW/TIG), is adopted to ensure the welding quality.
The weld seam is uniform and beautiful, without defects such as porosity, cracks, slag entrapment, etc. The height and width of the weld seam meet the requirements of the welding process.

After the welding is completed, non-destructive testing, such as ultrasonic flaw detection (UT) or X-ray flaw detection (RT), will be carried out to ensure that the internal quality of the weld meets the requirements of the relevant standards.

 First of all, the surface of the sandblasting or shot blasting pretreatment, removes the metal surface of the oxide skin, rust oil, and other impurities, surface cleaning to Sa2.5 level, and then immediately spray primer.

 The primer selects epoxy zinc-rich primer with good antirust properties and strong adhesion, and the thickness of the coating is not less than 50 μm, which ensures the formation of good adhesion between the metal surface and the primer, and effectively prevents the metal from corrosion.

 After the primer is dry, spray epoxy ferrite intermediate paint, a coating thickness of not less than 80μm, to increase the overall thickness of the coating and protective properties.

 The final topcoat is polyurethane topcoat, which has good weather resistance, wear resistance, and corrosion resistance, and the thickness of the coating is not less than 80μm, which makes the appearance of the grapple beautiful and eye-catching and has good protective performance.

 The total thickness of the whole coating system is not less than 200μm, and according to the adhesion test, there should be good adhesion between the coatings.