When using high strength steel wire you must know 4 considerations as followings:
1. Ensuring that the welding surface clean and dry. The main reason for the generation of cold cracks is the presence of stress in the presence of hydrogen in the weld metal. Rust, oil, moisture, etc., until the exposed metallic luster and to ensure that the clean-up within the scope of cracks and sandwich defects such as no cracks in the weld surface before and after cleaning.
2. Reducing the stress component. The use of a reasonable welding sequence welding, to avoid the strong group to reduce the residual stress components; welding assembly should be tight or pad the workpiece firmly to prevent the welding heat generated by the additional stress and deformation.
3. Post-weld dehydrogenation treatment. After the welding is completed, immediately after the weldment to 150 ~ 250 ℃, and per mm thickness of not less than 5 min after constant temperature treatment slow cooling (and the total temperature time of not less than 1 h), to ensure that the welding joint Of the residual hydrogen diffusion to escape, reducing the delay of cold cracking.
4. Post-weld heat treatment. After the heat treatment is to reduce the welding residual stress, high strength steel welding is not generally post-weld heat treatment, heat treatment will cause some of the mechanical properties of joints decreased, such as: impact toughness. Only in the design rules have special instructions, the side should be post-weld heat treatment. But should pay attention to its post-weld heat treatment temperature can not exceed its tempering temperature.