The results show that appropriate amount of Bi can decrease the diameter of graphite sphere, increase the number of graphite sphere, strengthen the low-temperature toughness.
结果显示，适量的铋可以减小石墨球径，增加石墨球数量，提高球铁的低温冲击韧度。
2
Decreasing welding thermal input will decrease the oxygen content and the number and size of oxide inclusions, and it improves the toughness of weld metal.
降低焊接线能量时，将降低熔敷金属中的氧含量及其氧化夹杂物的数量和大小，从而提高熔敷金属的韧性。
3
The number of effective IAF nuclei were inconsistent for different microalloying series, resulting the corresponding changes of the volume fraction of IAF in HAZ and strength and toughness of HAZ.