Baoji Kehui Titanium Co., Ltd. ,Titanium plate, titanium materials processing and production, in the actual processing of titanium products, the summary of some production characteristics on titanium products for everyone to share. Due to a variety of titanium and titanium alloys have characteristics alone in physics, chemistry, mechanics, corrosion and process performance, therefore, the structural design of the structure can not be applied blindly common ferrous metals and other nonferrous metal equipment. This provision according to the characteristics of the performance of titanium, titanium equipment proposed general provisions of the structural design.
1, due to the mechanical properties of titanium and titanium alloys with different steel, titanium yield is high, narrow plastic deformation, resilience large cold stamping and cold-formed, and called titanium device structure to be simple, but good structure is also easy to clean welded joints near the surface, easy to use gas welding, positive protection, quality of welded joints on the back.
2, and titanium can be wrong, Ni, bear, lead solder metal phase, no brittle after welding, since these metals in titanium solubility greatly. However, titanium and steel and other metals each melt poor characteristics, the titanium and other metals can not be directly welded. To connect to connect only through bonding, soldering, welding and explosive bolts.
3, the impact of titanium is poor and fracture toughness, so to maintain the continuity and smooth structure at the weld should be designed to avoid stress concentration.
4, titanium plastic deformation range is narrow, and there are significant hardening phenomenon. Therefore, bending and flanging titanium parts usually large bending radius, expanding at a smaller rate expander.
5, the titanium chloride solution is easy to produce crevice corrosion, crevice corrosion and titanium but temperature, chloride concentration, pH value and the size of the gap has a close relationship.
In sea water and sodium chloride brine, when the temperature is below 149 ℃, the titanium will not corrode. When the temperature exceeds 121 ℃, the titanium in a very narrow gap, especially in the non-metallic gaskets corrosion can occur at the time when the temperature exceeds 149 ℃, the wider the gap, the gap such as titanium pipe and tube sheet corrosion will occur. When the metal surface texture harder chloride deposits, the effective concentration of chloride deposits will be considerably lower solubility with chloride where the wall temperature, and because the insulating effect of fouling, the temperature may rise significantly, So also it is prone to fouling under crevice corrosion at the field. Crevice corrosion tendency of temperature and chloride concentration, the higher the titanium becomes.
Crevice corrosion susceptibility of titanium is also related to the size of the gap. The possibility of wide-gap than the narrow gap crevice corrosion is far greater. When non-metallic materials in contact with titanium, titanium crevice corrosion tendency than a titanium gap is much greater. In fact, the device is also common in crevice corrosion occurs mostly in the flange sealing surface in contact with the non-metallic gaskets. Titanium also crevice corrosion in hydrochloric acid, sulfuric acid, oxalic acid and formic acid solution.