E6013 for steel 铁
7018 万能杠 , higher tensile than any other
SS308 Stainless Steel 白钢 （not suitable food industry)
Why need to heat up welding rod? So that the molten rod won’t shrink too fast after welding, to prevent crack.
For example a tower crane purchase from China, we couldn’t find a suitable rod for the repair work, then heating is necessary.