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main road ductile iron manhole cover

Writer:Jason MaykalSource:Original Number of visits: Date:2019年1月14日 14:21

 main road ductile iron manhole cover s should not have defects such as porosity, shrinkage, slag hole, insufficient pouring and slag inclusion, which can reduce strength and damage appearance. Repair welding is allowed under the following circumstances.

 

(1) For ductile iron main road ductile iron manhole cover s, the single area after eliminating defects is less than 5 cm2 below 50 kg and no more than 8 cm2 above 50 kg, and the depth is no more than 50% of the wall thickness at that point. The number of such defects on the same main road ductile iron manhole cover  bar is no more than 3.

 

(2) For the removal depth of defects in gray iron main road ductile iron manhole cover s, the non-machined surface shall not exceed 50% of the nominal wall thickness at that place, and the machined surface shall not exceed 30% of the nominal wall thickness at that place. The weight ratio of welded meat metal to bulk metal after repair welding shall be in the following range

main road ductile iron manhole cover s with defects exceeding the above requirements or with cracks shall be scrapped.

10. Defects such as non-concentrated and fine slag and dirt, small pore, sand and sand holes are allowed on the secondary surface of main road ductile iron manhole cover s which are not machined, but these defects can not exceed 5% of the main road ductile iron manhole cover  area and 10% of the corresponding thickness.

11. Repair welding defects shall comply with the following conditions:

(1) Defect removal until good metal is present.

(2) The mechanical properties of the electrodes used for important parts can be guaranteed to be no less than that of the main road ductile iron manhole cover s themselves.

(3) After repair welding, heat treatment should be carried out, and nodular iron main road ductile iron manhole cover s should be annealed at high temperature (welding repair without affecting the performance of the parts may not be heat treatment after technical inspection).

main road ductile iron manhole cover made by ductile iron material, Designed and manufactured in China by EN124 standard, 
direct sale from foundry by a leading supplier in this industry

TypeInfo: Industry News

Keywords for the information:main road ductile iron manhole cover