KOBE HF-800 K

Composition(%)
C 0.80
Si 1.65
Mn 1.24
Cr 3.82
Mo –
V 2.42
W 0.29
Diameter and length (mm)
Dia. 3.2 4.0 5.0 6.0
HF-600 350 400 400 450
Common to individual welding processes
– Preparation of base metal:
Rust, oil and soil attached on the base metal may cause blowholes.
– Preheat and interpass temperature:
In order to minimize cracking, control of preheat and interpass temperature is a key technique
– Immediate postweld heating:
Heating the weldment at 300-350oC for 10-30 Minutes. Control the temperature carefully, or the hardness of the weld will be decreased.
– Postweld heat treatment:
Postweld heat treatment(PWHT) at 550-750oC is effective to prevent cld cracking and distortion in service.
– Underlaying:
Underlaying is effective to prevent cracking in weld here low-alloy steel having high hardenability is hardfaced or where high-hardness weld metal is deposited on carbon steel.
– Penetration:
In hardfacing, the properties of the weld metal will considerably be affected by welding penetration into the base metal.
– Welding distortion:
Intermittent and symmetrical welding sequences are effective to minimize welding distortion.