Mr.. Pramod
Request to confirm why Phosprous is very low in weldable steel ( 0.05 Maximum ). How it affect weldability.
It affects the weld-ability of metals by forming hot cracks. i.e., Sulphur and Prosperous forms low melting eutectic with Nickel which segregate at grain
boundaries during weld solidification and cause hot cracks. High percentage of Phosphorous may generate longitudinal cracks before solidification of weld metal. It may also act with Sulphur and Carbon to promote segregation to an extent where it could affect the .micro structure of wrought material..
Sulphur embrittlement can be can be prevented by addition of Mn in proportions. and this Mn-Sulphide formation will prevent formation of Nickel
Sulphide. Hence, Sulphur & phosphorus which could not be eliminated during steel making process, are kept very low to avoid above mentioned problems.
Sridhar.
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It affects the weld-ability of metals by forming hot cracks. i.e., Sulphur and Prosperous forms low melting eutectic with Nickel which segregate at grain
boundaries during weld solidification and cause hot cracks. High percentage of Phosphorous may generate longitudinal cracks before solidification of weld metal. It may also act with Sulphur and Carbon to promote segregation to an extent where it could affect the .micro structure of wrought material..
Sulphur embrittlement can be can be prevented by addition of Mn in proportions. and this Mn-Sulphide formation will prevent formation of Nickel
Sulphide. Hence, Sulphur & phosphorus which could not be eliminated during steel making process, are kept very low to avoid above mentioned problems.
Sridhar.
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