Cold forming head with precise dimensions and stable quality, not caused by heating and oxidation surface roughness, head beautiful appearance; addition, do not worry produced by heating the material deterioration. To reassure customers use the company's head, the material used is procured directly from steel mills, steel cold forming head according to the special requirements for smelting and rolling steel. Where cold forming process will have some residual stress and cold work to strengthen, head no exception. In case of container mounting stresses, welding residual stress, thermal stress, it will produce stress superimposed, if there is stress corrosion environment, in a short time may cause stress corrosion cracking. If the material is carbon steel, the nitrate, ammonia, and sodium alkaline environment cracking occurs; case of austenitic stainless steel, in particular a chloride ion environment, the crack occurs, this crack is called stress corrosion cracking . Carbon steel and low alloy steel containers in hot dip galvanized or aluminized immersed in liquid zinc or aluminized, the head of the straight edge cracks may occur, a phenomenon called "galvanized (aluminized) brittle crack "This is because the welding residual stress, processing residual stress exists, the low melting point metal zinc or aluminum results of the grain boundary diffusion. Thus, the container in the hot dip galvanizing or aluminizing bath, should do first heat treatment, to remove residual stress. Carbon steel head on the (plastic machining marks) carbon steel subjected to tensile deformation, with the main stress in the direction of 45 degrees will produce slip line, this time along the surface of the oxide film off this slip-line . Cold stamping head in the vicinity of the transition section of the small r, the oxide film off the traces of a lattice shape, which is caused by the surface of the plastic processing traces. Not any harmful defects. On stainless steel welds (plastic machining marks) have weld head, in forming before removing the inner surface of the wafer and the entire outer surface of the weld straight edge weld reinforcement and transition zone after processing; in spin before molding pressure, the inner and outer surfaces of the weld reinforcement shall be removed. Stainless steel head, the weld strength of the base metal are different, the central lower welding, the plastic processing, it will produce a slight concave line, which is caused by plastic working surface traces, not harmful defects such as cracks . Longwan Hongyu Metal Head Factory Add: Wenzhou City view golden sand town seven A Tel :0577 577 -86925750 -86925157 Fax Mobile: 13057722577 15355996788 Contact: Sun Shaodi URL: www.hyft.cn