شبكة التخطيط العمراني بسم الله الرحمن الرحيم
للكاتب :
Mustafa Ahmed Rijab Al-Najar
Mechanical Department – Technical Institute–baquba- Iraq
ABSTRACT
The result of this research work showed that the increase of the cooling rate will increase the
amount of martensite that will reduce the weldability of the dual phase steel . the low
percentage carbon enables water to be as a suitable quenching medium for production of the
dual phase steel of better weldability than the quenching medium of a salt solution
The results also showed that the increased annealing time causes growth of the austenite grain
size without affecting its amount . annealing for a period of more than 10 minutes produces a
structure of polygouized ferrite-martensite , while annealing for 10 minutes or less the
structure will be polygonized ferrite – pearlaite with small amount of martensite . bearing in
mind that the weldability depends on the amount of the martensite phase its distribution
within matrix .