Fastener technology ...
1. Existing problems According to gb11376-1989, neutral salt spray test was carried out for the corrosion resistance of phosphating film, and no corrosion was found in 90min. The unqualified rate of
Main influencing fac...
Heat treatment can make the high-strength throat hoop obtain the comprehensive mechanical properties such as certain strength, good plasticity, toughness, low notch sensitivity and high bending streng