Standard for salt spray test
The salt spray test standard specifies the salt spray test conditions, such as temperature, humidity, sodium chloride solution concentration and pH value, and also sets technical requirements for the performance of the salt spray test chamber. Which salt spray test standard is adopted for the same product is selected according to the characteristics of the salt spray test, the corrosion rate of the metal, and the sensitivity to salt spray. The following are several standards for salt spray testing, such as GB/T2423.17-1993, and equivalent IEC, MIL, DIN, ASTM and other related standards. GB/T1771-91 "Determination of neutral salt spray performance of paints and varnishes".
1. Salt spray corrosion test chamber is for surface treatment of various materials, including metal plating, hardware, electronic parts, chemical coatings, baking varnish, automobile, motorcycle, hardware ware, screws, springs, magnetic materials, organic and inorganic coatings. , anode treatment, anti-rust oil and other industries for quality testing, testing the corrosion resistance of its products.
Second, the salt spray test and the actual connection
The salt spray test is an environmental test that uses artificial simulated salt spray environmental conditions created by salt spray test equipment to evaluate the corrosion resistance of products or metal materials. It is divided into two categories, one is the natural environmental exposure test, and the other is the artificial accelerated simulated salt spray environment test. The artificial simulated salt spray environment test uses a test equipment with a certain volume space—the salt spray test chamber, to artificially use the salt spray environment in the volume space to assess the salt spray corrosion resistance quality of the product. . Compared with the natural environment, the salt concentration of the chloride in the salt spray environment can be several times or several times higher than the salt spray content of the general natural environment, so that the corrosion rate is greatly improved, and the product is subjected to a salt spray test to obtain a result. The time is also greatly shortened. If a product sample is tested in a natural exposure environment, it may take 1 year to corrode, and in a simulated simulated salt spray environment, as long as 24 hours, similar results can be obtained.
The artificial simulated salt spray test includes a neutral salt spray test, an acetate spray test, a copper accelerated acetate spray test, and an alternating salt spray test.
(1) Neutral salt spray test (NSS test) is one of the earliest applications in the field of accelerated corrosion test. It uses a 5% aqueous solution of sodium chloride solution, and the pH of the solution is adjusted to a neutral range (6-7) as a solution for spraying. The test temperature is taken at 35 ° C, and the sedimentation rate of the salt spray is required to be between 1 and 2 ml / 80 cm · · h.
(2) The acetate spray test (ASS test) was developed on the basis of a neutral salt spray test. It is to add some glacial acetic acid to the 5% sodium chloride solution, the pH value of the solution is reduced to about 3, the solution becomes acidic, and the salt spray finally formed is also changed from neutral salt spray to acid. Its corrosion rate is about 3 times faster than the NSS test.
(3) Copper accelerated acetate spray test (CASS test) is a rapid salt spray corrosion test developed recently in foreign countries. The test temperature is 50 °C, and a small amount of copper salt-copper chloride is added to the salt solution to strongly induce corrosion. Its corrosion rate is about 8 times that of the NSS test.
(4) The alternating salt spray test is a comprehensive salt spray test, which is actually a neutral salt spray test plus a constant damp heat test. It is mainly used for cavity-type machine products. Through the penetration of the tidal environment, salt spray corrosion is generated not only on the surface of the product but also inside the product. It converts the product alternately under the two conditions of salt spray and hot and humid, and finally checks whether the electrical and mechanical properties of the whole product are changed.
Raw materials for animal medicine
Conventional veterinary drug raw materials are: oxytetracycline hydrochloride, doxycycline, chlortetracycline hydrochloride, lincomycin sulfate, gentamycin sulfate, tylosin tartrate, florfenicol, water-soluble amoxicillin, sulfamethoxazole, enno Floxacin lactate, ciprofloxacin hydrochloride, ciprofloxacin hydrochloride, metronidazole, ribavirin, vitamin C, astragalus polysaccharide, penicillin potassium.
The traditional Chinese medicine extracts in veterinary medicines are derived from natural Chinese herbal medicines.
It is purified, concentrated and purified in a different ratio from the original drug. It not only retains the natural state and biological activity of the original drug composition structure, but also retains the harmless and
The beneficial exogenous substance essence realizes the micro-quantification and standardization of Chinese herbal medicine raw materials, and provides a new way for the breeding industry to realize green production. The following herbal extracts for veterinary use: Anti-pathogenic microorganisms Chinese medicine: Anything that can inhibit or kill the reproduction of pathogenic microorganisms and improve the immunity of the body is called anti-pathogenic microorganisms
Chinese herbal medicine. According to the theory of traditional Chinese medicine, it can be divided into heat-clearing medicines, exopathic medicines, diarrhea and water-repelling medicines, damp-damping and diuretic medicines, phlegm-relieving and cough-relieving medicines, qi-regulating and Xiao-shi pharmacological blood medicines, and phlegm-relieving and anti-asthmatic medicines.
Raw materials for animal medicine,Nicarbazin in Feeds,Nosiheptide Veterinary,Nosiheptide Antibacterial,Human Gastric Mucin
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