How to weld cracks in the heat oil pump casing?
Thread Content
Cracks were found in the pump body of the hot oil pump (catalytic reprocessing oil pump, manufactured by Calvert Ebara), as shown in the image below. The pump body is made of ZG1Cr; the operating temperature of the pump is 300°. What are the welding materials required, the welding current, whether heating and insulation are necessary before and after welding, and any other considerations?
Pre-weld and post-weld heat treatment; grade 1 radiography test passed
Is there a leak? Or is it the shedding of the corroded layer resulting from high-temperature oxidation and corrosion on the surface of the equipment?
It should be ground thoroughly and cleaned carefully; TIG welding should be used for the root pass, with multiple welding passes. Preheating before welding and maintaining heat after welding are necessary; it’s also possible to consult the manufacturer
308 welding rods made of pure nickel can be used; welding at room temperature requires no preheating. The operation is somewhat difficult and the cost is relatively high
It is recommended not to weld yet; conduct a material analysis first. Cracks in the pump body of this slurry pump are rare.
There is no leakage, and the surface shows no signs of oxidation or corrosion
The pump body material is ZG1Cr13
This post was last edited by Zhongheng Pump Industry on 2020-2-28 08:29. Haiyou is right! Additionally, use 308 welding rod. 308 is a Cr19Ni10 stainless steel welding rod with a titanium-type coating; it can be used with both AC and DC power. During welding, the coating does not turn red nor crack, and the weld metal possesses excellent mechanical properties as well as resistance to intergranular corrosion. It is used for welding Cr19Ni9 and Cr19Ni11Ti stainless steels in applications where the operating temperature is below 300°C.