Titanium plates are widely used in civilian fields because of their excellent performance, high specific strength, good medium temperature performance, and non-magnetic properties. In production, we found that the common failures of the surface quality of titanium plate products include over-corrosion, hanging dust, and incomplete removal of scale and stripes.
1. Over-corrosion: Over-corrosion refers to pits or uneven defects on the surface of the titanium plate after pickling, which is different from the appearance of the material structure. Generally, the cause of over-corrosion defects is the imbalance of hydrofluoric acid and nitric acid. The concentration of hydrofluoric acid is too high or the concentration of nitric acid is insufficient. ~4min, the process parameters can be adjusted according to the operation site, and the pickling time can be shortened appropriately.
2. Hanging ash: Hanging ash refers to the oxides attached to the surface of the titanium plate after pickling. During pickling, the dry titanium alloy and the acid solution undergo a chemical reaction, and the oxides produced accumulate on the surface, preventing the further occurrence of the reaction. The defect of hanging ash is generally caused by excessive deposition of hanging ash during pickling and insufficient washing after pickling. During pickling, the parts should be shaken continuously to make the reacted product fall off the surface of the titanium alloy. After pickling, spraying or flushing should be strengthened to remove the hanging ash. In our country, the water flow mixed with compressed air and tap water is generally used to wash the parts, and the effect is good.
3. Incomplete removal of scale: There are many reasons for this defect, and each process is possible. It may be that the oil removal is not good, or the molten salt treatment time is not enough, or the pickling solution is invalid. All potential causes of this problem should be ruled out one at a time. When necessary, a sandblasting process can be added to the pre-treatment.
4. Striped piebald spot: The cause of this defect is generally caused by uneven reaction. It can be eliminated by shaking the parts during pickling and reducing the temperature of the pickling solution. In addition to the above defects, it is sometimes found that the titanium plate products that pass the inspection after pickling, after a period of time, appear mottled on the surface. The number of studies on this topic is surprisingly little.It may be due to the presence of residual acid on the surface after pickling or the presence of corrosive media brought in by subsequent production, which is produced under the combined action of stress. The difference, generally speaking, does not affect its performance, and can be removed by pickling again, but the force-bearing parts should strengthen the hydrogen removal treatment after the second pickling.
Shaanxi Etermetal Co., Ltd. is an excellent supplier of titanium plates in China, which can provide qualified products and high-quality services to many buyers around the world. If you are looking for a qualified titanium product factory, the 24-hour online customer service is looking forward to your consultation!
