Railway turning by Sandvik Coromat

More catalogs by Sandvik Coromat | Railway turning | 50 pages | 2015-03-10


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Railway turning is listed under these categories

Industrial Supply > Manufacturing & Metalworking

Featured catalog pages of Railway turning

introduction railway wheel turning is about machining large components in big machines with large depths of cut depending on train type the wheels have their different characteristics and requirements within new wheel turning there are tool holders featuring over and under coolant and reliable inserts for complete machining of any railway wheel in the area of re-turning you find shanks and inserts that securely machines the old wheels to be as good as new to achieve the best possible result there are different considerations to be made the guide contains two different chapters where the first one covers turning of new wheels and the following re-turning of wheels with tools from sandvik coromant the chapters include a product and wheel feature overview situation analysis best practice recommendations and troubleshooting advices for the most common situations overview 4 situation analysis best practice

1 parting blanks 2 heating of blanks in rotary kiln 3 compression forging 4 hole punching process 5 roll forming 6 bending process 7 hardening process – cooling with water 8 mechanical testing 9 turning of wheel 10 non-destructive test ultrasonic testing to detect e.g eventual cracks

high precision coolant all the new tool holders are equipped with high precision nozzles and offer both over and under coolant • the effects of high precision coolant coolant delivered to the right spot at the cutting zone has a large impact on chip control and tool life for improved process security • the effects of under coolant when machining at the same cutting data enables an increase of tool life by 67 and helps against the negative effect of thermal cracks

finishing operation before flipping the wheel finishing operation of the contact surface is performed tools in use • tool holder c10-prscl-70130-16 • insert rcmx 160900 cutting data operation vc m/min ft/min fn mm/rev in/min contact surface 100 328 1.25 0.05 note preferably also the roughing finishing operation of the bore is made in this set-up to keep the tolerances to secure that the bore is centred 2 machining the web in this operation the a operation lasts longer and is the “leading tool” when a tool is machining the outer diameter of the web a1 the b tool is facing the hub b2 at the same time when a makes its second cut a2 the b tools is facing the rim b1 when machining the web a it is important to get good surface quality while at the same time remove correct amount of material you could say it is a roughing and finishing operation at the same time

challenge too much amount of raw material when machining the rim puts high pressure on the insert since a big part of the cutting edge is engaged in the cut this creates high cutting forces and vibration which in some cases leads to insert breakage solution re-programming re-program for a “roll in” operation to take out the extra amount of stock 1 before making the final complete cut 2 insert wear challenge insert breakage is often described as a problem but is normally the result of plastic deformation or thermal cracks on the insert solution • if thermal cracks increase the coolant flow as much as possible and ensure that the jet is directed correctly hitting the insert plastic deformation • if plastic deformation modify feed rate and use a more heat resistant grade p25 → p15 → k15 • change to a more heat-resistant grade thermal cracks

re-turning railway wheels initial considerations when re-turning it is desirable to choose a cutting depth which is as large as possible in order to achieve short machining times this is however highly depending on the wear conditions of the predominant part of the worn wheel when choosing tools and inserts consider the following • what type of wheel to be re-turned • the wear condition of the predominant part of the worn wheel • machine power that is available • in certain cases the profile can be turned in one single pass with other machines and other circumstances it may be necessary to divide the machining into several stages in order to produce the right profile and diameter dimensions for the wheel dividing the machining into several stages is common in underfloor machines where friction force is used to drive the wheel

overfloor machine in this machine you mainly re-machine freight trains and passenger car wheels there are two different ways to clamp the wheel one old and one more modern method old clamping clamping characteristics • wheel sets meaning axle and wheel discs are separated from the vehicle limitations • deformation of wheel inner diameter clamping method • wheel sets meaning axle and wheel discs are separated from the vehicle dismounted from locomotive or train • axle is fixed by two centre sleeves from left and right side on centre bores to drive the wheel set a chuck is clamping the inner diameter of the wheel flange alternatively friction drive • there are always damages on the inner diameter of the wheel deformation

situation analysis the main purpose with the situation analysis is to ensure we have stability depending on if it is a underfloor or overfloor machine there are different things to consider • l-style inserts don t have shims look at the insert cartridge and basic holder for damages the heat makes it become blue • cartridge protecting the basic holder • overheated broken insert • plastic deformation breakages • basic holder which usually is special considerations overfloor machine • cutting depths rigid clamping enables machining with high cutting depths normally more than one pass is needed – for surface finishing and adjustments of the dimensions • choice of inserts different insert grades can take different depths of cut see table on page 36

best practice underfloor machine in the following pages you find best practice for how to re-turn a railway wheel made of rolled steel machining at normal conditions when low cutting depths the c-style inserts is the first choice these inserts give good chip breaking and chip control when machining the flange due to the entering angle first choice grade is gc4215 note these tools are sometimes also applicable in overfloor machines when no need for large ap tools in use tool holder r175.33-5055 cutting unit r175.32-3223-1911 insert cnmx 19 11 40 -pf tool holder r175.33-5055 cutting unit r177.32-3219-1911 insert cnmx 19 11 40 -pf cutting data vc m/min ft/min fn mm/rev in/min 70-80 230-300 0.5-1.5 0.02-0.059

troubleshooting typical challenges when re-turning wheels are • insert breakage • short hot chips • vibration due to worn out cartridge insert breakage challenge insert breakage makes the carbide stick into the wheel main cause • overloaded insert • hard spots cracks of flats spots on the wheel solution • inspect the insert in time to avoid breakage • reduce feed and speed drastically and then slowly try to increase it • gently try to remove it or grind it out note occurs in both under and overfloor machines 46 flat