CN1483849A

CN1483849A - Antibacterial property improved austenic stainless steel and mfg method thereof

Info

Publication number: CN1483849A
Application number: CNA021487421A
Authority: CN
Inventors: 张体宝; 张体勇
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-11-15
Filing date: 2002-11-15
Publication date: 2004-03-24
Anticipated expiration: 2022-11-15
Also published as: CN1226440C

Abstract

The present invention provides an antimicrobial stainless steel material improved by copper-contained stainless steel and its products. Except for impurity its composition includes: (by weight percentage) carbon is 0.01-0.08, silicon is greater than or equal to 1.00, manganese is greater than or equal to 2.00, nickel is 8.00-11.00, chromium is 7.00-22.00, copper is 1.50-2.90, titanium is greater than 0.80 and the iron is equilibrium quantity. After having been undergone the processes of solid solution and age two-stage antimicrobial process treatment the copper can be uniformly dispersed in the base material in epsilon-Cu phase. Said stainless steel has excellent antimicrobial function, so that it can have extensive application range.

Description

Improve the austenitic stainless steel and the method for making thereof of anti-microbial property

Technical field: the present invention relates to austenitic stainless steel that improves anti-microbial property and preparation method thereof.

Background technology: knownly demonstrate effective anti-microbial effect as metals such as silver or copper.Yet silver is expensive, and is not suitable for using it under the corrosive environment.In addition, copper cheap, and can be as effective antiseptic-germicide.Therefore there is the people in stainless steel, to add copper, uses the material of this anti-microbial effect.

The stainless steel of being represented by SUS304 has been widely used in the apparatus that galley equipment or hospital use, the inner facility of buildings, motorbus for another example, the handle that uses in the public transports such as electric car, door knob., because today that the infection of streptococcus aureus has brought serious problems in the hospital, people thirst for adopting a kind of anti-microbial property that has always, and the unnecessary material that regularly carries out disinfection.

Open 8-53738 of Japan's special permission and 8-225895 disclose and obtain anti-microbial property with a kind of organic film or antibacterial film coating.

Yet the shortcoming of this antibacterial film is, because its anti-microbial effect of consumption of this film or coating promptly disappears.Otherwise the film of this anti-microbial effect that disappeared can play the effect of nutrition source mutually on the contrary, impels the breeding of bacterium.

Have the poor adherence of the composite plane layer of germ resistance component, thereby the substrate serviceability that applies is not good to substrate.Because the dissolving of this plane layer, scratch and make its outward appearance and germ resistance become worse and worse.

The the 96114349.5th and No. 00128266.2 Chinese patent and Chinese patent application have disclosed ferritic stainless steel and the austenitic stainless steel with anti-microbial property respectively, but from the transmission electron microscope figure of the stainless steel test block shown in the drawings distribution of richness-copper phase and inhomogeneous as can be seen, therefore its anti-microbial property obviously remains further to be improved, the dispersing property of a kind of copper in its matrix austenitic stainless steel that improve to some extent, that anti-microbial property is much improved that the technical scheme that the present invention proposes proposes at above-mentioned defective just.

Summary of the invention: No. 00128266.2 Chinese patent application has disclosed the austenitic stainless steel with following composition, except inestimable impurity, he is made of following component: the C that is less than 0.1 weight %, the Si that is less than 2 weight %, the Mn that is less than 5 weight %, the Cr of 10-30 weight %, the Ni of 5-15 weight %, 1.0-5.0 the Cu of weight %, Nb and/or the Ti of at least a or multiple 0.02-1 weight %, the Mo that is up to 3 weight % is up to the Al of 1 weight %, is up to the Zr of 1 weight %, the V that is up to 1 weight %, the rare earth metal that is up to the B of 0.05 weight % and is up to 0.05 weight %, and equal amount is iron substantially, and have mainly structure by the secondary phase of forming with the Cu that separates out greater than the ratio of 0.2 volume % in the matrix.

The preparation method of the austenitic stainless steel antibacterial member that this Chinese patent application provided is that " the described austenite stainless steel plate of hot rolling; and 500-900 degree centigrade of this steel plate of an at least thermal treatment mainly contains the secondary phase of forming greater than the Cu of the ratio of 0.2 volume % with in the matrix to separate out to have.”

The inventor estimates the effect of copper aspect the improvement anti-microbial property through studying assiduously, and the present invention has adopted two sections heat treating process to improve ε--and-Cu is distribution in stainless steel, strengthens anti-microbial effect.

The stainless main component of novel antibacterial provided by the invention is close with 304 steel, and other has except the explanation, and the amount among the present invention is all calculated by weight percentage.Ni is the key element that obtains austenite structure, the present invention is controlled at Ni in the scope of 8.00---11.00, Ni and Cr can both improve the erosion resistance of metal, and make metal have single uniform austenite structure, therefore the add-on of chromium is also bigger, be controlled in the scope of 7.00---22.00, Si can improve the erosion resistance to the vitriol oil, can form SiO when high temperature ₂Film improves oxidation-resistance, but excessively can worsen hot workability, therefore it is controlled at≤below 1.00 the scope; Mn can generate MnS and work the S effect that removes, and improves quality of materials, but excessively can reduce erosion resistance, so it is controlled at≤2.00 scope in; C is the assurance of intensity, and can impel the copper-rich phase uniform distribution, but content can make the chromium carbonization when increasing, and Cr content is reduced relatively influences erosion resistance, and its content is controlled at the scope of 0.01-0.08; Cu is the antimicrobial key element, and proper C u is through corresponding thermal treatment, and disperse is in matrix equably to make Cu, but too much Cu can make the mechanical property of steel reduce, and its content is controlled in the scope of 1.5-2.9.Ti can generate carbide with C, can improve solidity to corrosion, but excessive meeting reduces machinability, his content＜0.8.

The anti-microbial effect of anti-bacteria stainless steel is to infiltrate bacterium inside by cupric ion, has destroyed the normal composition of bacterial cell and the balance of procreation, reaches the purpose of bacteria growing inhibiting, killing bacteria.

Antibiotic reaction normally being carried out, will be made at first that the Cu element transformation is ε in the steel---Cu phase (copper-rich phase) becomes the particle particle that disperse distributes by dispersion state.At ε--the place of-Cu phase does not form the passive film of chromic oxide, and cupric ion is separated out in water easily and reached bacteria growing inhibiting, killing bacteria.

The present invention selects the suitable heat (batch) number of copper content in the stainless steel that we have produced in batches for many years except that increasing antibacterial treatment process, and other production processes as usual.By the austenite antimicrobial stainless steel that material of the present invention: Q/TBS-001 represents, not only have the traditional performance of common stainless steel, and can kill bacterium such as the intestinal bacteria and the streptococcus aureus of contact with it effectively.

Antibiotic austenitic stainless steel provided by the invention is through the solution treatment of temperature at 920---1150 ℃, make all carbide all be dissolved in austenite, shrend is cold soon, does not allow austenite separate out in process of cooling or undergo phase transition, after handling like this, can obtain single-phase austenite structure at room temperature state.The preferred range of solution treatment is 1000-1100 ℃; Most preferred temperature ranges is 1020-1050 ℃.Reduce to minimum for making remained austenite content and unrelieved stress after the thermal treatment, avoid may impelling residual austenite to martensitic transformation or stress relaxation owing to stressed with temperature fluctuation in life-time service, austenitic stainless steel provided by the invention carries out ageing treatment in 490-900 ℃ of scope.The preferred range of ageing treatment is 550-800 ℃, and most preferred temperature ranges is 650-750 ℃.

The suitable stainless steel that studies have shown that copper content is in a large number made the ε-Cu phase of gained after the antimicrobial treatment, and this even dispersion in steel distributes, and guarantees effectively to contact with bacterium, keeps persistent antimicrbial power.

Description of drawings:

Cu size distribution in the test block after the antimicrobial treatment

CUKα????3000×

Specific embodiments: anti-bacteria stainless steel is made metallographic specimen through grinding and polishing.Observing copper with electron probe microanalyzer distributes.

The present invention carries out for No. 448 with reference to " Chinese Pharmacopoeia ", Japan's " the antibiotic fabricated product of JIS2081-2000---antibacterial tests method, antibacterial effect " and " sterilization standard " health prison method [1999].

Test strain is a standard country bacterial strain, and intestinal bacteria are CMCC (B) 44102, and streptococcus aureus is CMCC (B) 26003.

Test method: will cultivate the test strain inclined-plane and make bacteria suspension, and make in every milliliter of bacteria suspension bacteria containing amount be (1～5) * 10 with the sterile physiological salt solution ⁵Individual/ml, in aseptic beaker, add metallographic sample, and add bacteria suspension number milliliter, make liquid level be higher than metallographic specimen.Under 35 ± 1 ℃ condition, placed 24 hours.Then this bacteria suspension is suitably diluted, get diluent 1ml and add in the plate, add nutrient agar medium 12-15ml and cultivated 24-48 hour, temperature is 35 ± 1 ℃, calculates the flat-plate bacterial colony number.

Austenite stainless composition of steel and its anti-microbial property see the following form

	??C	??Si	??Mn	??Ni	??Cr	??Cn	??Ti	Antibiotic rate
	??C	??Si	??Mn	??Ni	??Cr	??Cn	??Ti	Antibiotic rate	????1	??0.05	??0.80	??1.50	??9.11	??10.23	??1.62	??0.54	??99.95
????2	??0.09	??1.00	??1.99	??10.90	??21.00	??2.80	??0.80	??99.95	????1	??0.05	??0.80	??1.50	??9.11	??10.23	??1.62	??0.54	??99.95
????2	??0.09	??1.00	??1.99	??10.90	??21.00	??2.80	??0.80	??99.95	????3	??0.02	??0.76	??1.32	??8.21	??7.99	??1.47	??0.51	??99.95
????4	??0.01	??0.87	??1.20	??10.20	??8.55	??1.53	??0.48	??99.92	????3	??0.02	??0.76	??1.32	??8.21	??7.99	??1.47	??0.51	??99.95
????4	??0.01	??0.87	??1.20	??10.20	??8.55	??1.53	??0.48	??99.92	????5	??0.07	??0.59	??1.40	??8.95	??18.07	??2.50	??0.78	??99.91

Claims

1. antibacterial member of making by austenitic stainless steel, except that the impurity that allows content, constitute by following element: by weight percentage, 0.01---0.08 carbon ,≤1.00 silicon ,≤chromium of 2.00 manganese, the nickel of 8.00---11.00,7.00---22.00, the copper of 1.50---2.90,＜0.80 the titanium and the iron of equal amount, its copper after two sections antibacterial process of solid solution and timeliness are handled with ε---Cu mutually equably disperse in body material.