Water-solubility quenchs control of medium refrigeration character reachs application

The influence with characteristic to refrigeration chroma we use Zhengzhou city family intelligent the KHR-01 refrigeration that high-tech development limited company produces is characteristic detector, right new the 20 ％ of 5 ％ ～ that make up, series AQ251 solution undertook standard frugal is measured, its are shown 1 times like the graph as a result. By the graph 1 can see, the ν Max of AQ251 increases along with pH indicator and decrease, t ν Max increases along with pH indicator present trend of the reductive after going out to increase first, fall in chroma 8 ％ are the following, t ν Max falls to be controlled to 600 ℃ , when chroma is 5 ％ , ν 300 increase to 87 ℃ / S, receive the cooling character that is bordering on clear water, quench the microtherm cooling power of medium increases quickly at this moment. After chroma exceeds 20 ％ above, t ν Max shows downtrend, but as a result of its ν Max and ν 300 very low, accordingly its cooling power still inferior. From above the circumstance can see, the limits of optimal use chroma of AQ251 is 10 ％ ～ 20 ％ , under 10 ％ hind, 300 urgent leap add ν Max, ν , plus PAG kind quench medium all is existing ageing trend makes T ν Max drops, such making that the product is in microtherm region is cold fast increase, temper by dipping in water cracks the tendency to increase, do not choose to use as far as possible accordingly. 2.

Temperature is used to the influence of cooling character same detect equipment, the air of 13 ％ crankshaft that we use to the spot pledges AQ251 undertakes 20 ～ character of refrigeration of 50 ℃ series detects. Its detect if pursue,as a result 2 are shown. By the graph 2 can see, as the addition of temperature, the ν Max of medium increases, t ν Max and ν 300 keep basically changeless. But still can see by the curve, although 300 change of T ν Max and ν are very little, from lukewarm phase refrigeration does not have apparent change, but the cooling power of microtherm phase still is increased somewhat, because this temperature cools to its,characteristic influence still cannot be ignored. Qualitative to tone, especially a few temper by dipping in water crack the product with clear trend, should restrict appropriately quench the bank of medium uses temperature range; Quench to the induction workpiece, because temper by dipping in water appears the main factor that the gender is not influence quality, can consider to increase AQ251 concentration appropriately, those who reduce microtherm level is cold fast, and incorrect its temperature tries to restrict. 3.

The influence with characteristic to refrigeration ageing the elapse as time, water-solubility quenchs of medium gradually ageing, although its chroma did not produce change, but its refrigeration character is becoming poor however. This is water-solubility quenchs the common characteristic of medium, because organic matter is in,be placed for a long time or heat ceaselessly the meeting in cooling process produces high polymer to decide catenary issue. Oily kind quench medium also is put in the problem with similar move, the cooling rate because of their itself is slow, ageing cycle is relatively longer won't cause quality problem, consequently small be taken seriously. Water-solubility quenchs the ageing of medium is shown 3 times like the graph. From the graph 3 can see, the ageing characteristic of AQ251 is T ν Max is reduced, ν 300 increase. This kind of change is very adverse to heat treatment, because T ν Max is mixed of 300 change of ν integrated, report is the cooling rate of phase of medium low temperature to increase quickly, product oil cracks the tendency more apparent. 4.

Control method is in did not realise water-solubility quenchs before the ageing phenomenon of medium, we are according to chroma and temperature characteristic to refrigeration influence undertakes controlling commonly. Particular way reachs heat treatment to ask to choose likely chroma range according to characteristic of product data, structure namely, quench according to water-solubility the sex going against dissolve of medium, the temperature before quenching certainly under the dot that go against dissolve 30 ℃ of 20 ～ are controlled. Chroma is used commonly at holding saccharometer to detect refraction reading is multiplied obtain with refraction coefficient. As the understanding to medium ageing phenomenon, we think refraction coefficient is moved the influence of viscosity, cause chroma to detect data is not accurate, must detect through viscosity regularly obtain refraction coefficient. This kind of practice can make chroma detects really more accurate, but ignored the effect with characteristic to refrigeration ageing however. The loss that brings as ageing phenomenon increases gradually, a lot of enterprises also realise chroma detects the control requirement that also cannot satisfy cooling character, the method that this appeared to quench character of medium cycle refrigeration detects. Water-solubility quenchs medium ageing is process of an advance gradually, the change of cooling character won't be mirrorred quickly inside a cycle come out, the accommodation with a lot of additionally characteristic to refrigeration products is wider, because this cycle detects,acceptable standard of result neither one has judge, prep let alone undertakes character is adjusted cooling. But control refrigeration character should tell place of the person that had become a kind of consensus and be used to accept in this moment, just use why to plant the form undertakes controlling returning needing further exploration. To quenching medium cools as heat treatment product character changes when the requirement is narrower and narrower, the quality problem that medium ageing creates can be exposed adequately come out. Because should ask according to the material of the product and mechanical function,a kind of circumstance is, need is close to temper by dipping in water to split the cooling and characteristic cost of the brim; Another kind of circumstance is to quench medium ageing, refrigerative character achieves generation temper by dipping in water to crack the brim of the tendency. Ought to take more rigid control step at this moment, prevent cooling character to be exhibited to ageing brim, actually at this moment we also found condition of border of cooling and characteristic pilot. With me factory crankshaft attune pledges used AQ251 is below exemple, introduce the control method of cooling character. When my factory uses AQ251 to undertake crankshaft attune pledges at first, the data that basically is used at processing is the railroad engine crankshaft of 42CrMoA. The mechanical function of crankshaft asks to be in moderate level, had not produced engine crankshaft one case to move qualitative crackle accident up to now from 1996, the cooling character of 13 ％ AQ251 is worth ν 300 from 49 ℃ / S increases 64 ℃ / S. My factory was entered 2003 marine crankshaft market, those who begin to produce 42CrMo4 is marine crankshaft, material and 42CrMoA are basic and identical, mechanical function asks to rise considerably however, be opposite especially the requirement of concussion result, by convention heat treatment cannot achieve technical requirement. In choose quench when medium, the consideration uses 6 ％ ～ the AQ251 of 8 ％ , classics craft experiments, small lot production, mechanical function all achieves product technology requirement. But in June 2005, happen however successive 7 attune pledge crankshaft appears quench the circumstance of crackle. Classics analysis, because AQ251 ageing place is affected,basically be, but according to cooling character cycle detects circumstance analysis, the range of 13 ％ AQ251 that character is worth metabolic extent and uses without the spot is big, but the border that its absolute value already reached temper by dipping in water to crack. Subsequently, we according to all sorts of experiments, the use case that joins other water-solubility medium established control method. We think, to tone simple product, should ask according to product technology and combine its material to choose ν the floor level value of 300, produce experience according to the spot again (if the cooling character when crankshaft crackle detects circumstance) the upper limit of 300 is worth affirmatory ν . Choose one cooling character to detect periodic (for example) of a month, have a record to the use circumstance inside this cycle, when exceeding certain limit to using a number, also undertake character detects cooling. Quench in view of water-solubility medium is put in the characteristic of ageing, two kinds detect the acceptable standard of the result should differ somewhat. To cycle inside detect ν 300 can be restricted by fluctuation limits decides eligible; And when detecting to cycle, ν should be pressed 300 times be less than upper limit certain amount will regard as decide whether acceptable level. Quench to the induction, we should control ν not only 300, should control T ν Max more. Look in general situation, because the induction quenchs in temper by dipping in water hard layer surface can generate pressure only, produce crackle not easily consequently. In fact we discover, because quench medium refrigeration character changes when refrigerative course is severe, in temper by dipping in water hard layer surface will produce thermal stress crackle. The ～ that this crackle once produced in us is planted 10 above appear continuously in crankshaft, analytic reason is remained quench medium ageing is refrigerative character becomes poor be caused by, and because T ν Max is too low,be. This makes we realise, quench to the induction and character, of area of whole low temperature cold fast relatively ν the absolute value sense of 300 is greater. The cooling medium that quenchs to be being used at the induction accordingly, we think to should resemble treating ν 300 same, try to be controlled strictly to T ν Max. Additional, we think to use hold candy appearance to undertake the spot detects still have real sense, what ought to improve nevertheless is needless go again the chroma of conversion medium, and need to detect in cycle only time a plant maintains reading to be in a reasonable scale. 3, the use of medium safeguards nearly 10 years to come, quench through water-solubility the use of medium, we return discovery, it is very important also that the use of medium is safeguarded. Because water-solubility quenchs medium is using the rate that ageing all can accelerate when be not being used frequent or for a long time, still ought to establish clean cycle in day-to-day management so, and when was not used inside proper time, should try proper mix, with slow down its ageing process. 4, epilogue analyses us to be able to reach from above, control good water-solubility to quench medium should do good the following: (1) asks according to product data and technology, combine the influence with chroma, characteristic to refrigeration temperature, choose appropriate chroma and temperature limits. (The cooling character with 2) logical choice detects cycle and detect temporarily regulation, define corresponding acceptable standard, eligible condition is in in order to assure refrigeration when medium is used. (3) is made use daily maintain a standard, fixed cleanness. CNC Milling CNC Machining