JCO双面三丝自动埋弧焊生产ASTM 1035钢管焊接裂纹的控制

Control of Weld Cracking of ASTM 1035 Steel Tube as Developed during Manufacture Operation with JCO Double-side 3-wire Automatic SAW Process

当ASTM 1035钢碳当量0.58%时,淬硬倾向严重,焊接时易产生裂纹。通过研究ASTM 1035钢焊接裂纹的产生机理,制定合理的焊接工艺,结合生产现场实践证明:通过采取焊接预热措施;选用具备低碳、硫、磷、无镍或低镍,韧性指标优良,强度匹配适中的焊材;控制焊缝成形系数,降低熔敷金属的稀释率,减少焊缝金属中的碳、硫、磷含量;采取"小电流"、"慢焊速",严格控制焊接热输入;并配合以合缝管端间隙、引熄弧板装配,内外焊保温输送和定位焊清根等生产现场工艺细节控制,可有效减少ASTM 1035钢管焊接裂纹的产生。

In case of carbon equivalent as 0.58%, the ASTM 1035 low-carbon steel is apt to have significant quench hardness which often leads to development of cracking during welding operation. Based on study of the mechanisms of the said cracking, proper welding process is prepared. The on-the-site operation with the process proves that the cracking severity can be remarkably reduced by means of a number of on-the-site process detail- control actions, including pre-heating prior to welding, selecting welding consumable containing low contents of C, S and P, and no or low content of nickel and having excellent toughness and well-matching strength, properly controlling the formation factor of the weld, reducing the dilution rate of the deposited metal, reducing the contents of C, S and P of the weld metal, using the small current and slow welding speed techniques, strictly controlling the welding heat input, determining proper pipe-end gap for joining, mounting arc run-on/off tab, temperature-keeping transport of the material during inner welding operation, and back gouging during tack welding, etc.