Nickel powder is an important alloying element in the current widely used austenitic stainless steel for medical. Its main role is to make stainless steel to form a stable austenitic structure, thereby improving the corrosion resistance, plasticity, weldability and toughness and other properties of stainless steel, a stable austenitic structure can also make stainless steel with non-magnetic.
Medical 316L and 317L austenitic stainless steel nickel-content requirement is 10% to 14%, in medical 304L stainless steel the nickel content is 8% to 10%.
However, nickel is a potentially allergenic factors, a large number of clinical manifestations have proved that nickel and its compounds is hazard to humans. One of the most common damage is nickel contact dermatitis, higher incidence, strong allergic will cause eczema. When it contact with the human body, nickel ions can penetrate into the pores and sebaceous skin inside to cause skin irritation, and its clinical manifestations is dermatitis and eczema. EU € 1 and € 2 coins release of nickel elements can cause strong allergic reactions to people have allergy.
What should arouse vigilance is that the enrichment of nickel ions in vivo may induce toxic effects, cause cell damage and inflammation, have the risk of teratogenic and carcinogenic hazardous to organisms. Nickel-containing medical metal materials implant in the human body, due to the inevitable corrosion, wear, nickel ions and other metal ions released into nearby tissue, easy to induce allergies, infections, and other tissue reaction, especially in patients allergic to nickel is particularly serious. Once have a report show that the release of metal ions such as nickel, chromium and molybdenum in stainless steel cardiovascular stents caused by an allergic reaction may be one of the indirect causes of cardiovascular stent restenosis.
Because of the nickel element is harmful to human body, many countries enacted nickel content increasing demand for daily and medical metal material, the highest nickel content allowed in the relevant standards are getting lower and lower. In view of the nickel-containing metal material for medical harm that may be caused to human health, metal powder supplier suggest that the best way is strictly prohibit or restrict the nickel content in various metallic materials directly contact with the human body (such as implantable devices, dental materials, jewelry, etc.) .
Research and development of new stainless steel thinking is using nitrogen instead of nickel elements to stabilize the structure of austenitic stainless steel, the major scientific issues, including the chemical composition of the new stainless steel resulting optimal design (in particular, the optimization of the nitrogen content in steel, OK)high nitrogen stainless steel smelting and processing, the influence of nitrogen on the biocompatibility of stainless steel and related mechanisms. For example, high nitrogen nickel austenitic stainless steel compared to traditional medical stainless steel is just different in composition, that is abandoned nickel but added nitrogen, while the austenitic structure has not changed, but shown a more excellent blood compatibility.
Through years of research, the scientific team found that, first of all nickel removal improve the blood compatibility of stainless steel, With the improvement of the nitrogen content in steel, the hemocompatibility of high nitrogen nickel austenitic stainless steel will gradually improved. The researchers said that: With the deepening of the basic research, medical high nitrogen nickel austenitic stainless steel material smelting and processing technology is maturing and will certainly promote the clinical application and development of new medical stainless steel. The new non-nickel austenitic stainless steel in medical equipment, food and catering equipment, jewelry, and other regular contact with the human body, will have a lot of demand for market, and may gradually replace the existing medical stainless steel containing nickel.
Source:http://www.mhcmp.com
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