First, the purpose of quenching medium management:
In order to ensure the normal operation of machinery and equipment, and the accident, failure to take preventive measures, and reduce human negligence and achieve better economic benefits, this for the purpose of lubrication management.
U reduces production costs. (maintenance cost, downtime loss)
U improves productivity. (reduction of rest time)
U to increase the added value and reduce the bad rate. (precision maintenance)
Promotion of economic benefits of U. (oil species unification, energy saving)
U reduces human negligence and reduces accidents.
Two, quenching medium in the library management
U appropriate in inventory.
Consolidation and rectification of U.
U appropriate custody; quality management
Three, attention to the use of quenching oil:
1, refueling method
In addition to the oil groove of quenching oil when please use the gas pumps, avoid oil dumped directly into the oil tank, the oil pump end into the barrel, one end of the oil pipe is inserted in the oil tank, the oil slowly diffuse full, avoid contact with air at one end of the tubing, gas when mixed with too much air, bad heat treatment the appearance of work, easy oil deterioration.
2. Inhibition of oxidation deterioration
Reduce the contact between oil and air when the furnace starts and stops
(2) control the height of oil surface and avoid contact with air (if possible, add a cover plate as possible)
(3) the looseness of cooling circulation circuit causes air mixing
Avoid using copper containing materials
The workpiece must be cleaned
3. Inhibition of moisture mixing
Inspect the workpiece before entering the furnace, whether it has cleaning water
The cooling cycle is recycled water mixing
(3) moisture is produced by atmosphere combustion at the top of oil tank
4, how to get the cooling performance of diazepam
The use state of quench oil viscosity should be maintained within 5-20mm2/s
Homogenization of flow rate (setting the required velocity of compliance)
5, oil temperature control
The oil temperature is controlled in the temperature range of the oil. It is strictly forbidden to exceed the service temperature range.
Four. Management items and management standards of quenching oil
Test item
Management value
Significance and others
The
The
2003
2003
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2003
2003
The
The
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2003
Dynamic viscosity
Hot oil @100 mm2/s
Cold oil @40 mm2/s
Acid value mgKOH/g
Residual carbon wt%
Flash point (COC) C
hot oil
Cold oil
Trace moisture ppm
Cooling curve
Water soluble quenching solution
Dynamic viscosity @40 DEG mm2/s
Tortuosity 20ND
Total alkalinity
PH
Cooling curve
Average cooling rate at 350 /150 C
15 +% >
15 +% >
New oil +0.5>
0.5>
New oil -30<
New oil -20<
200>
15 +% >
The concentration of 10 +% >
The concentration of 10 +% >
8.5<
Hot oil: decomposition of base oil, oxidation degradation (coincidence) and mixing of other oils
Cold oil: cooling to the upper agent consumption, oxidation degradation (decomposition)
Deterioration of oxidation (including equipment abnormalities, conditions of use)
Oxidative degradation: the cause of poor brightness
Thermal decomposition and mixing of other oils
thermal decomposition
Due to the mixing of water, the cooling characteristics change
Changes in cooling characteristics
Judge whether or not to decompose with the tortuosity ratio
Criteria for determining the concentration of water soluble quench solution
Determine the actual concentration of quenching liquid
Anti rust and corruption difficulty standard
Standard for concentration and macromolecular metamorphism
Based on the significance, fees and other aspects of comprehensive judgment, to show its priority, \ \
Five, water soluble quenching liquid use matters needing attention and management
(1) preparation of quenching liquid and method of quenching operation
1, before the new quenching liquid, quenching tank and circulating cooling system should be fully cleaned. If the original system is used for oil, it must be cleaned with industrial cleaning agent.
2, the preparation of quenching liquid water has no special requirements, ordinary tap water can be. Because the long state of quenching medium proportion of heavier than water, mixed with the oil tank before the first half and then poured into the water bucket, lonpond quenching liquid, after sufficient mixing, slowly into the oil tank, must be completely dissolved.
3, from the heat treatment operation, using the method of quenching liquid and long state of tap water is basically the same, only the quenching temperature of steel than oil quenching low, but slightly higher than tap water quenching.
4, the use of PAG quenching liquid should pay attention to measure and control its concentration. The concentration of a start of the preparation can match a little higher, from 10 to 15%, and then according to the actual need, the concentration in the case of cracking down slowly, until the best.
(two) concentration measurement, liquid temperature control and agitation of quenching solution
1, the production site can generally use handheld sugar refractometer to test the state of quenching liquid concentration. It is necessary to use other methods to measure the concentration of quenching liquid with longer time and more serious pollution. In production, the fluctuation of quenching liquid concentration should be controlled within the range of + 0.5% of the determined value.
Determination of the concentration of a single solute solution
For an aqueous solution of a single solute, the refractometer readings are in direct proportion to the solute concentration. If the letter N on behalf of the refractometer readings, the solution refractive index, C (%) on behalf of the solute concentration percentage (by weight), the solution has the following relationship between the two is:
N=KC (1)
Among them, the coefficient K depends on the type of solute. The K values of several common solutes in heat treatment are listed in table 2. C is a weight percent concentration.
K values of several kinds of common quenching medium
Solute
The value of K
Multiplication coefficient
Solute
The value of K
Multiplication coefficient
NaCl
One point one
Zero point nine one
NaOH
One point six
Zero point six three
NaNo3 sodium nitrate
Zero point seven
One point four three
Na2CO3
One point five
Zero point six seven
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