Use supersonic frequency temper to reduce whorl brittleness to assure product quality

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  • source:BAGANZ CNC Machining
If handle of active bevel gear, ditty wants helix to quench via cementite,have a lot of work processing, requirement of whorl place hardness is inferior, the method that uses besmear to prevent ooze coating commonly undertakes protective, assured the hardness that workpiece asks already so, reduced whorl brittleness again. Helix is active the technical requirement of bevel gear: Material 20CrMnTi, ooze layer 0.

9 ~ 2.

0mm, hardness of surface of the whorl after cementite quenchs 30 ~ 45HRC. Whorl invalidation place basically is in R part part. Use Rockwell hardness plan detect from the hardness in limits of end panel 10mm. The technology of ditty handle asks: Material 20CrMo, ooze layer 0.

6 ~ 0.

8mm, sclerotic layer 0.

8 ~ 1.

0mm(513HV) , hardness of surface of the whorl after cementite quenchs 40 ~ 47HRC. Diamond pyramid hardness is used after whorl line cut plan detect, use load 1kg. 1.

The to whorl processing before cementite (the delay after 1) cementite leaves surplus to leave mental allowance ooze according to cementite layer deepness is cold, the car goes carbolic layer, machine whorl to quench next. This production process comes true not easily, workpiece touchs knock easily in the process of have a change of luck, the influence manufactures efficiency. (Workpiece of 2) copper facing undertakes copper facing after treatment whorl, but effect of whorl copper facing is not quite good, unfavorable use. Copper quickens quenching oil ageing. (After 3) besmears to whorl part besmear of part of whorl of the agent that prevent ooze prevents ooze agent, make its avoid cementite, be in condition of martensite of low carbon temper. If prevent ooze good, can prevent whorl rupture (cost 0.

2 ~ 1.

0 yuan / raise) . The agent that prevent ooze has two kinds of attenuant ways: One kind is dissolvent of ability in swimming (include alcohol) ; One kind is organic dissolvent (basically be xylene) . Dissolvent of ability in swimming cleans clean degree to workpiece the demand is higher; Organic dissolvent is easy volatilize, but contaminative work place, endanger worker health. The agent that prevent ooze prevents ooze mechanism to use two kinds commonly. One kind is used metalloid as block ooze agent; One kind is the metal regards block ooze as the agent () of stannum and copper and its compound, its compound, was full of a lot of foreign matter gas in heat vital energy so, contaminative furnace is angry, make cementite difficult, cementite layer not all. If use the agent preventing ooze of cupreous tin, affiliation amount is large. Use time grew to will appear in furnace lid and upper part of Ma Fu canister reductive copper or a ropy thing (pure stannum is outer for carbon black) , make oxygen probe shifts to an earlier date invalidation, pollute equipment, cause it is difficult to clear.

Besmear prevents the regulations of ooze agent: Whorl cleans drying of furnace of → low temperature (natural air, workpiece becomes rusty easily) → of examination of → of agent of ooze of → Tu Fang fills air of nature of → of the agent that prevent ooze (microtherm furnace drying) furnace of person of → outfit clip. Whorl is when agent of Tu Fang ooze, the deepness that wants layer of the hardness that asks according to workpiece, ooze, adoption cementite quenchs equipment, besmear again the agent preventing ooze of corresponding ply. When besmear prevents ooze agent, ooze of generation bleb leakage is in easily in R horn. Because this should prevent the need after ooze agent besmears to be checked afresh, undertake filling besmearing to alveolate place. Workpiece is perpendicular enter the agent that prevent ooze and inclined direction to enter the agent that prevent ooze, the length in end panel and ply not all, general and perpendicular it is good to enter the result, when coating nature is cool dry (the 8h) after besmear or in microtherm furnace (the ability after 170 ℃ control the drying in × 60min) enters cementite furnace. Gear should take care when outfit clip, fell to prevent ooze agent with preventing to touch; Should besmear inhomogenously sometimes, the member that hold the jockey when furnace and qualitative check arrives without the examination, workpiece is touched in the course that takes heat, after such heat treatment are over, hardness not all, the biggest when differ 20HRC unit. Hardness is exorbitant, need to use Rockwell hardness plan chase an examination, and high temperature temper. In box type furnace, besmear is very thin one can prevent ooze, the whorl after heat treatment clears very convenient also; And in besmearing the whorl of same ply puts heat of person well type, do not prevent ooze, certainly will should increase coating ply, besmear twice besmear 3 times even. Its reason is workpiece in cementite of well type furnace, ooze agent is prevented to have in air after giving heat very big one part burns caustic, out of tolerance of the hardness after quenching (the agent that prevent ooze has the effect that prevent ooze not merely, still rise to reduce when quench cold fast action) . Besmear of the agent that prevent ooze is much, drip downward in the meeting below the action of gravity and high temperature, if drip to go up to the product, influence product quality, create waste product even sometimes. In the whorl that handles in well type furnace, be in subsequently it is very difficult also to clear, the bolus that use spray clears, whorl easy injury, whorl needs to use silk of screw die Liu, labor strength is great. Although the present agent that prevent ooze does not fall off when quench, but still can have a few entering oil is medium and pollution is oily. Workpiece quenchs junior travel is cleaned, a lot of agents that prevent ooze enter clear lotion in, quicken its ageing; In preventing ooze agent to enter cleaning machine, still cause it is difficult to clear. 2.

Whorl classics cementite quenchs after temper, have high temperature temper to whorl part (temper of high temperature of 1) salt bath, lead bath temper many workpiece, clean is taken after heat preservation cold. In using, some manufacturer mirror anneal quality to be not stabilized, whorl has broken end appearance. Whorl is being taken when clean is cold, if damp, room temperature passes low, or whorl is stained with sundry hind make its cold fast accelerate, can make the place forms whorl some quench organization, anneal hardness not all, bury next quality hidden trouble. Workpiece should after 60min of warm-up of furnace of preexistence low temperature, be in the place that wants anneal again in high temperature temper has in Wen Yanyu or plumbic bath furnace (precaution heats quickly cause crackle) ; After be like workpiece to be taken out from inside saline bath, lead bath, put a person quickly the air after 1h of the heat preservation in fireproof fiber is cold (notice asbestine to answer dry, use period of time should microtherm temper) , can assure anneal quality so. (Temper of 2) supersonic frequency (supersonic frequency frequency is compared high frequency low, penetrable layer is deep, hardness of the whorl after be helpful for temper is even) mechanism of temper of high temperature of supersonic frequency temper and saline bath, lead bath is same, heat time is short, carbide and matrix α photograph still have not enough time to be brought up, consequently the organization basically is the same as saline bath likeness, surface layer is body of all alone family name, core is temper martensite. When supersonic frequency, will control by time relay heat the accident of time, according to the temper temperature that the hardness of the requirement will come to decide. The temper time with differ as a result of voltage when high frequency temper and use different electric current to make sure temper temperature is reached proper (cost 0.

08 ~ 0.

20 yuan / raise) . Helix is active bevel gear whorl (16mm) of whorl diameter ≥ is when temper, answer above all warm-up 4 ~ 7s, make R arc place reachs annealing temperature (700 ℃ control) , stop to heat next, heat again after 4 ~ 7s make whole whorl place reachs temperature (700 ℃ control) . Insert whorl immediately after temper the air after 1h of the heat preservation in fireproof fiber is cold, avoid to cause hardness as a result of other reason not all. Whorl is when temper must warm-up, because heat quickly,prevent and cause defect. The key of high frequency temper is induction coil make (1) seeing a picture. Coil is controlled partly for circuit, stand by R arc place to be whole round one, need to hold to raise coil of here thermal efficiency flat, whorl of the distance when temper and part pouring wine cup is minor, from the back bigger. Efficiency of high frequency temper is taller (2 / Min) . General a hardness of the surface after temper for 35 ~ 44.

Between 5HRC (requirement temper hardness under 32HRC, unfavorable with) of high frequency temper. Be the same as a temper hardness difference to be 3 HRC unit. To ditty handle whorl (12mm) of whorl diameter ≤ , in the workpiece when temper need not warm-up, but should make sure temper time is not less than 3s, prevent to heat quickly cause local whorl to quench. Normally, whorl adopts line cut, chip uses magnet grip to grind make; Alcohol of 4 % nitric acid is used to corrode observation after sample has been made, whole area should be gray, not due bright side, bright side is to quench face. Because workpiece is lesser, use copper pipe turn to make difficulty, use cupreous club to the car is made and be become consequently, use 1 v/LIT all over the ground, as a result according to detecting relevant to inductor section undertakes modification, use amend implement nap (if pursue,show) 2 times. 3.

Epilogue is in production of nearly 6 years, in all temper makes an appointment with 1.5 million, did not appear because temper is unqualified. And the business that creates whorl to rupture happens. Because temper quality is stable, reduced the labor intensity that produces cost and worker greatly. CNC Milling