The values shown in Table 1 are taken from GB/T 5117-1995, the Chinese National Standard for carbon steel welding electrodes and electrodes for welding corners. The values are for all welding arcs and processes, both manual and automatic, including gas shielded and such. The standard also applies to both AC and DC electric arc welding, as well as to submerged arc welding.
The standard applies to all types of welding electrodes, as long as they are used for making carbon steel, alloy steel, and stainless steel alloys. It does not, however, apply to welding between dissimilar materials or special-purpose welds.
The main purpose of the standard is to control the size of the weld. The size of the weld should not be greater than the referenced dimensions specified by the standard. It also provides guidance on the physical and mechanical properties of the weld itself. As a result, welds should have the strength and toughness required of a specific application.
The standard also specifies other important aspects related to the weld, including temperatures, preheating, and post-weld heat treatment. As the weld electrode size increases, the preheating temperature increases. For weld electrodes with a diameter of 4mm or less, preheat temperatures are generally higher than those specified in the standard. On the other hand, for larger weld electrodes, preheat temperatures are generally lower than those specified in the standard.
Finally, the standard also outlines a number of other important aspects related to welding, including electrodes and equipment selection, welding current, and welding speed. All of these aspects are important for ensuring consistent weld quality and avoiding potential welding defects.
In conclusion, GB/T 5117-1995 is essential for the manufacture of high-quality welds for the welding of carbon steel components. The applicable values should be carefully measured and recorded to ensure the quality and consistency of the welds.
