摘要
After rolling even after drawing,a fraction of martensite may occur in the microstructure of ER70S-6 wire deteriorating the ductility and drawing performance.The mid-products of drawing for test were heat treated at 350℃ and 500℃,deformed ferrite plus pearlite plus some unchanged martensite and deformed ferrite plus pearlite plus troostite were obtained respectively.Repeat bending test was carried out on both as-drawn and heat-treated samples.The results showed that the brittleness of the as-drawn rods is not due to defects but due to the presence of martensite in microstructure.The sample heat-treated at 500℃ and cooled in oven has the best ductility.
After rolling even after drawing,a fraction of martensite may occur in the microstructure of ER70S-6 wire deteriorating the ductility and drawing performance.The mid-products of drawing for test were heat treated at 350℃ and 500℃,deformed ferrite plus pearlite plus some unchanged martensite and deformed ferrite plus pearlite plus troostite were obtained respectively.Repeat bending test was carried out on both as-drawn and heat-treated samples.The results showed that the brittleness of the as-drawn rods is not due to defects but due to the presence of martensite in microstructure.The sample heat-treated at 500℃ and cooled in oven has the best ductility.
