3 results about "Solderability" patented technology

A hot-rolled steel strip having superior low temperature toughness and weldability, which is suitably used as a starting material for high strength electric resistance welding pipe, is provided at a low cost without constructing new production facilities and increasing cost. The hot-rolled steel strip is low carbon steel containing at least one of about 0.5.% or less of Cu, about 0.5% or less of Ni, and about 0.5% or less of Mo, wherein Pcm represented by the following equation (1) is 0.17 or less:Pcm=(% C)+(% Si) / 30+((% Mn)+(% Cu)) / 20+(% Ni) / 60+(% Mo) / 7+(% V) / 10  Equation (1),(where (% M) indicates the content of element M on a mass percent basis), and the balance includes Fe and incidental impurities. In addition, in the entire microstructure, the ratio of bainitic ferrite, which is a primary phase, is controlled to be about 95 percent by volume or more.

Disclosed is a copper surface treating agent satisfying both heat resistance and solderability. Also disclosed is a surface treatment method. Specifically disclosed is a copper surface treating agentcontaining an acid, a benzimidazole compound and water, which is characterized in that at least a first benzimidazole compound and a second benzimidazole compound having a melting point lower than that of the first benzimidazole compound by 70 DEG C or more are contained as the benzimidazole compound.