problem in heat treatment induction hardening

Hi Ravi,

In Ind hardening the bending % is directly proportional to the Power(kw), Heating time, & inversely proportional to the frequency, speed of rotation & volume of the mtrl.

First of all, I need to know the specs of the machine you r using for hardening. The type of inverter, power, frequency range and the control system (PLC,relay logic, manual) details.

offcourse, you can get the hardening parameters text book (somewhere I've seen) that gives you a hint to get the good results. search in web you may get data free...!!

I've retrofitted around 8 R.F & M.F machines till today (with PLC System).

I can help you get a good Control system with Many advanced features in any kind of Induction Hardening machines.

Regards,

DEAR VEERESH,

I AM USING A STATIC CONVERTOR BASED ON THYRISTOR CONTROLS IN FREQ RANGE 8 TO 10 KHZ AND A STSTION EQUIPPED WITH FACILITY OF LOADING 4 CRANKSHAFTS AT A TIME ON A SINGLE DRUM PROVIDED WITH PLANETARY GEAR TRAIN FOR ROTATION OF THE COMPONENT. THR RPM USED IS IN THE RANGE 032 FOR JOURNAL DIA AND 28 FOR PIN DIA . LTH OF COMPONENT CRANKSHAFT IS 890MM BEARING DIA IS 88MM FOR JOURNAL AND FOR CONN. PIN DIA THE DIA IS 62MM. THE WEB THICKNESS IS 20 MM AND STROKE OF CRANKSHAFT IS 50 MM. THE BEND OBSERVED IS IN THE RANGE OF 1.8 TO 2.5 MM WHERE AS THE REQT IS BELOW 0.3MM . NO STRAIGHTENING IS ALLOWED SINCE ALL FILLETS OF JOURNAL AND CONN, PIN ARE HARDENED AND THERE IS A POSSIBILITY OF MICROCRACK GENERATION IF STRAIGHTENED. IF U CAN DESIGN A SUITABLE MACHINE TO TAKE CARE OF SUCH PROBLEMS KINDLY SUGGEST . THE IS EVEN TWISTING PHENOMENON FOR WEBS ADJACENT TO THRUST DIAS WHERE HEAT PATTERN HEIGHT IS MORE THAN OTHER DIAS.

REGARDS RAVI

Ravi,

I got it, You have a crankshaft hardening machine, with motorised indexing for the hardening of 4 shaft pins 1 by 1. the whole setup is in quenching tank. is't it?

the solution is so simple...!!

just, Send me your enquiry data on my Mail ID; kveeresh2@gmail.com

Also mention your location & position in the industry (where this system is in). soon you will recieve a quote.

I need;

1> Specs of the inverter (kw, Input supply voltage, name of mfrr, year of mfr, Output transformer data etc)

2> Exsisting machine controller name(siemens PLC?), Field devices data (Input/Outputs,Nos of motors & their HP, Hydraullics?) & Features(operator panel Details)

3> Nature of work - u need a retrofiitting or a Brand New machine??(including inverter & work station??)

4> Budget/time range for the total Project (this helps me decide the control systems; Semi automatic or Fully automatic & their availability)

5> you can provide some photographs for my design reference, if your industry allows.('one picture is worth thousand words').

6> Component details & cycle time per pin/4shafts.

The crankshaft pin usually have a uneven volume of material beside it. so, it requires variable heat throughout every rotation. It makes a considerable effect on the quality of the case depth pattern as well cracks......

Anyway.. there r lot of issues over this subject.......Pls reply..

pl dont consider budget, tell me if the problem can be solved

Is this another of those "special" CR4 questions, which seems to imply people working on things that they are completely unqualified to do????

Hi Andy,

I do not know what is bothering you.If some one has a problem, may be he is not expert in that particular Field, and there is some one who is ready to help him to solve the problem, there is nothing wrong. This forum is meant for solving the engineering problems, so please avoid making such comments as it will frustrate young engineers.

Suresh Sharma.

Read my new post, maybe I have explained it better for you there.

But I personally suspect that in certain countries, people falsify their education documents and get jobs for which they are totally unqualified and then proceed to ask questions on CR4 for massive production difficulties that an expert would need to be on site for weeks to answer fully......

The belief alone that CR4 can fix such problems is like still believing in Fairies to my mind.....

Here we get usually no pictures, just a question....when X-Ray pictures of high quality are probably required.....of specific areas of the product!....that the original poster does not even understand that much is appalling.....

This leads later to awful quality problems in production and later reliability problems in the product......

This would certainly appear to be one of those types of (CR4) problems.......again!

I notice that you have received little help up to now, maybe this is an indication that many CR4 members have similar thoughts and feelings on the subject (but are more Gentlemanly than I am)......we will see what happens over the next few days......whether its just people trying to get me to stop posting or whether you actually get an expert here that can actually help in a positive manner via this blog!!!!

Or even just one that THINKS he is right!!! What happens to the product then I am sure we will never learn!!! Especially if its negative! The company will simply go bankrupt!!

Have a great day.......

Hi Andy,

I know you are great gun in CR4. I have read many of your posts and you have helped many people in solving the intricate problems. Butttttttttttt to-day it seems you are not in your usual mood, may be some what angry at the way the question is being asked. May be our friend is young and facing serious problem. I know no one can provide"details regarding machine design, tailstock design, rotational speed variation as a parameter to avoid bend,inductor design, sequence of hardening , polymer concentration, type of quench method, dip method, spray, and power level and frequency to be used?". It is big assignment itself.So we seniors have to inform such young engineers to not expect answers for such questions in this Forum. They should ask questions which can be answered in short version.

I normally, whenever come across such questions I simply keep quiet.

Have nice evening Gentleman.

Suresh Sharma.

If complete information had been delivered in the original first post, I would not have said anything, but it wasn't!! That was not my failure.......

Now the blog is starting to look almost "respectable"!! Keep up the good work!!

I hope that we have an expert for this area......

dear sir ,

thank you for your comment as that previous comment hurted me. i would like to inform we are hardening almost 300 crankshafts daily for almost 15 years both fillet and non fillet hardened . especially for smaller versions of fillet hardened crankshafts(4 cyl engine) we can control the run out after hardening below 0.4mm which without straightening is taken care in gringing operation.but for the bigger 4 cyl crankshaftsof larger dia the runout is in the range of 0.9 to 1,5 mm.we have conrtolled everything to say,inductor design, load on crank during hardening,power pulsing,sequencing the cycle of operations, tailstock pressure, rotational speeds,power levels, 8-10 & 10 khz frequency on same set up, without any results. heard of some new tailstock centres called hydro pneumatic centres, which reduce bend as crankshaft is allowed linear expansion during hardenig.

without relevant data , i am not posting my problem

ravi

Hi Ravi,

Please also read my reply to Mr.Andy No.11.I hope you will understand the whole situation well. Please do not expect any one to give you detailed designs for the equipment. Such assignments are undertaken by the consultants on chargeable basis.If your company can not solve the problem within the organisation then you should utilise the services of the consultants.There are many Metallurgists available in India to solve your above problem.At least one of them has already responded to you.

Meanwhile I will narrate you my experience of heat treatment during my training days.

After my final year of Production Engineering I was put in a steel foundry mfg. Steel cast Couplers used by railways in coupling two coaches. There was a En8 steel Pin used in the couplers which was required to be hardened. The process was not carried out properly and required hardness could not be achieved. We, as fresh engineers were assigned to solve this problem as many of the couplers could not be cleared by railway inspectors. We studied the process in detail and observed that temperature in Electric furnace for heating the pins was not controlled. Also quenching in water was slower. We ourselves handled the whole process and carried out the heat treatment with our own hands and we were able to solve the problem. So all the Couplers waiting for pins could be dispatched.

We were rewarded by the management for solving the problem.

So may be you will have to personally look in the Heat treatment process and see if it is carried out properly. May be you can solve the problem.

Suresh Sharma

dear Suresh,

i knew complete inductor design for fillet hardened crankshafts , the effect of various inductor geometrical parameters considering the space restriction for fitment of flux concentrators ,the placement of concentrators and its geometry , variation of side and face coupling etc etc.. . i have proved the process for 2 cyl,4 cyl and 6 cyl fillet hardened crankshafts, and designed the inductors without the help of consultants,and studird effects of other parameters which i dont want to reveal now specially to the person who thinks to be most intelligent of all and who has aquired what degree........

god knows. if he requires such inductors ask him to call me for help

dear mr.Ravi,

Without a complete (or atleast essential) data I can't guide you through this problem.

I personally need to go through the technical issues before a commitment.

Very well put!

Seemingly I am not alone with my previous comments!!!

Thanks.

My back round is in automotive repairs, not in metal treating. But there are some questions that I think you should try to have answered.

Is the bending problem new? Have the cranks ever been correct? If so, what has changed since the cranks were correct?

Are there assumptions being made that might not be correct. Is the quenching temperature accurate? Did the thermometer go bad. Unless all of the measuring devices are verified, errors can enter the equation.

Good luck.