Valve Springs
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well said kehaulani
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@trumpetb said in Valve Springs:
Do you really not know about plastic deformation do you really not know about stress hardening of a spring when it enters the plastic range.
I will explain it.
No, I've never heard of 'stress hardening' until this thread.
I've heard of 'work hardening' (which is very occasionally referred to as 'strain hardening') but 'stress hardening' is a new one to me.
What you describe sounds very much like you actually mean 'work hardening'.
Quote from Wikipedia
For metal objects designed to flex, such as springs, specialized alloys are usually employed in order to avoid work hardening (a result of plastic deformation) and metal fatigue, with specific heat treatments required to obtain the necessary characteristics.
Now look, I'd intended to edit the provocative tone out of the first draught of my earlier post but nodded off during the process, and then it was too late. So I apologise for understandable offence taken.
But you do make rather a target of yourself.
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Apology accepted.
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Work hardening is well known of course but new expressions now exist to describe work hardening and the whole area is becoming convoluted.
It is perhaps my turn to apologise for using the unfamiliar term stress hardening the problem is terms appear often such as strain hardening and back stress strengthening and I sometimes succumb to the temptation to conflate valid terms, this old dog has his limitations
Abstract - strain hardening
Influence of the pearlite interlamellar spacing on the strain hardening behavior with systematically various pearlite fineness (within the range 140 to 510 nm) obtained by isothermal transformation has been investigated in spring steel 60Si2MnA. Based on the uniaxial tensile tests carried out at ambient temperature, an empirical relationship between the measured strain hardening exponent and interlamellar spacing was found.A further abstract - back stress strengthening
We report significant back stress strengthening and strain hardening in gradient structured (GS) interstitial-free (IF) steel. Back stress is long-range stress caused by the pileup of geometrically necessary dislocations (GNDs).
The leap to using the term stress hardening is a small one
I believe that technical papers often become inaccessible due to the variety of terms used and using more descriptive terms can be helpful.
Apology for the confusion
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@trumpetb said in Valve Springs:
You may be an actual engineer but the real life experience of taking a spring that does not perform well and stretching it, and after the stretching, it then performs well is well known, is proven and is consistently repeatable.
Suggesting I am not a real engineer will come as news to my employers who employ me as a principal engineer, and by the way I have worked in fabrication in several major industries and have 45 years engineering experience.
I have my PhD in metal alloys. And can state my reputation in less words. I win.
You want to muck around with the k constant Trumpetb, then so be it. But the results will be unpredictable. Yes? HOWEVER, I must admit, you just may luck out. And it appears you have. Good for you, but I still win.
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As all the possible arguments have been mentioned, and before the discussion grows heated, can we agree to disagree and close this thread? Please give your opinion in ONE WORD ONLY.
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I dont understand your issue Dr
I say when I stretch springs they become stronger, I have done this many times I did this yet again today and it worked yet again.
It is an observed phenomenon and is easily tested and proved.
It has been used by countless musicians to make their springs stronger over the last 50 years.
It is repeatable it is clear it is easy to test.
It takes thirty seconds to do and costs nothing si why are members refusing to even try it out and instead they say it cannot ever work.
This is unreasonable and illogical and unworthy of this site.
This is like telling Newton that gravity cannot exist and apples cannot fall down because you dont like his explanation of it.
I am not monkeying with k at all and I am not trying to win anything.
I am saying if you stretch springs they get stronger
Why is it important for members to deny the blindingly obvious and easily tested and proven.
Do you Dr believe that if you stretch springs they become stronger and if not why not.
I have done this three times in the last three weeks alone and every time it worked. It always works.
Where is the problem.
Forget k forget any and all explanations of why it might work forget any need to win arguments this is about using a simple phenomenon to improve the valve response if you suffer problems.
In my opinion it is undeniable so can we stop denying it now
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YESSSSSS (8 letter minimum post length)
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Love it Dale.
Ok the only way to end this nonsense is for me to declare here and now that it is impossible to make a spring stronger and improve the valve action by stretching it.
It does not work and it will never work.
Do not ever stretch valve springs it is pointless and nobody has ever improved a valve spring action by stretching the spring.
You guys win, you can begin to celebrate now
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Ok, the tone of the discussion is getting more and more acid. I am closing this thread before bad language and undesirable arguments creep in.
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Locked by
barliman2001
