局部快冷减少焊接热裂纹的研究

ＮＮ Ｐｒｏｋｈｏｒｏｖ认为随变形速度增加金属热塑性降低，降低冷却速度可以降低变形和焊接热裂纹倾向，并把预热和缓冷作为减少焊接热裂纹的措施。研究结果表明，焊缝局部快冷可以减少脆性变形速率和减少焊接热裂纺

Investigation of decrease of hot craddng in welding by local rapid cooling

Prokhorov considered that the hot ductilty decreased with increase ofdeformation speed, the decrease of cooling speed could reduce the deformation speed and susceptibilty to hot cracking in weldment, preheating and slow cooling were therefore proposedto prevent hot cracking in weldment. Our investigations show that local forced cooling to the weld can reduce the deformation in hot brittle temperature range and the increase of the deformation speed could enhance the hot ductility of the metal in the lower part of the brittle temperature range.It therefore increases the allowable deformation rate and decreases the hot cracking in weldment.On the basis of the theory the experiments were carried out with the ma-terial 30CrMnSiA. The hot pipe was used to follow the welding torch to cool the welding beam It is shown that the local forced cooling to the welding beam greatly decreases the hot cracking in welding.