Research And Application Of The Material And Process For The High Toughness TBM Disc Cutter Ring

Tunnel engineering construction and development is one of the20th centur-y’s greatest scientific and technological achievements in our country, TBM is more and more using in a deep, long distance, large diameter, under complicated geological conditions. Cutter ring installed on machine is the main part to broke rock, because of the bad working conditions, the consumption is very great. The material of the cutter ring needs to have high hardness, high wear resistance, good impact toughness, a certain amount of resistance to tempering performance and good processing performance. Through to test and analysis the cutter ring material performance at home and abroad, found the cutter ring material performance towards two directions, high hardness and high toughness steel. The material of cutter ring with high toughness adopted by the foreign is low alloy high strength steel AISI4340. This article aim at the development of high toughness TBM disc cutter ring, with various technological means, on the basis of guarantee the hardness requirement to improve the performance of materials, the main work content is as follows:(1) Analysis of the bearing characteristic of the disc cutter ring material and working condition requirements, to meet the requirements of cutter ring material persistent work during construction process, determine the high toughness disc cutter ring material mechanics performance is:the hardness above560HV, toughness reached30J.(2) Based on the strengthening mechanism of alloy elements and the principle of multiple small amounts, the composition design was carried out again on the basis of the existing steel AISI4340(3) Steel was studied by thermal simulation experiments of the phase change temperature point, austenitic coarsening temperature, the dynamic softening and austenitic austenitic phase transition behavior of the continuous cooling process. Results show that the TBM cutter ring steel material with the a us t e ni t i c tr a ns i t i o n te m pe r a tu r e is A c1≈701℃， A c3≈737℃; Se t th e fo r gi n gte m pe ra tu r e ra ng e of900℃~1150℃, c an ma ke fu l l us e of th e dy n am ic re c ry s t a ll i z a ti o n to re du c e st r e ss, ro l li n g te m pe r a t ur e c a n b e se t up in750~850℃, c an ta ke adv a nt a ge o f th e dy n a m ic re sp o n s e to im pr ov e or g a ni z at i o n a lpe rf o rm an c e; W he n th e c o ol i n g ra te is mor e th a n1℃/s m art e ns i t i c tr a ns f or m at i o n be ga n to oc c ur, th e m ar t e ns i t i c tr a n sf or m at i o n te m pe r a tu r e is a bo u t300℃.(4) Ac co r d i ng to th e T B M c ut t e r ri n g st e e l’ s or g a ni z a ti o n a nd pe rf o r m an c ere qu i re m en t s, st ud i e d t he in f l u e nc e of qu enc hi n g a nd te m pe ri n g pr oc e sspa ra m et e rs on m ec ha ni c al pr o pe rt i e s, th e in f lu e nc e of u si n g pr e tr e a tm en t and la rg e de fo r m at i o n c om pr e ss i o n m e an s to cha ng e th e o ri g i na l or ga ni z a ti o n be fo r e qu e nc hi n g, th e th e rm a l si m u la ti o n te st i n g m ac hi ne in t o e xp l o r i n g th e Q P and is o th e rm a l qu enc hi n g pr o c e ss on th e pr o pe rt ie s o f m a te ri a l or g a ni z ati o n.E xp e ri m en t re su l t s sh o w th a t th e op t i m um st e e l qu e nc hi n g te m pe r a tu r e is870℃, th e op t i m um te m p e ri n g te m pe ra tu r e is200℃; U si n g pr e li m in a ry he a ttr e a tm en t a nd la r ge de fo r m at i o n c om pr e ss i o n c an e f fe c ti v e ly im pr o v e th e m at e ri a l of th e or i gi n a l gr o u p, ha s a gr e at in f l u e nc e on th e pe rf o r m an c e;E xp e ri m en t a l st e e l re qu ir e s go o d fo r g in g pr oc ess i n g, t he be st pr o c e ss pa ra m et e rs of th e he at tr e a tm en t a t880℃is fi r e,870℃qu e nc hi n g,200℃te m pe r i n g,m ec h a ni c a l pr o p e rt i e s o f th e m a te r i a l c a n me e t th e re qu i r e m e nt s of hi g h to ug h ne ss of T B M c ut t e r ri n g st e e l; The Q P and i so t he rm a l qu e nc hi n g pr o c ess us e d in th e de ve lo p m en t of T B M c ut t e r ri n g st e e l ha s a c e rt a i n a pp l i c a ti o n pr os p e ct.(5) B y va ri o u s t e c hn ol o g ic a l m ea ns, th e e xp e ri m en ta l st e e l te st i n g or ga ni z a ti o n un de r th e t e st p ro c e ss, fo u n d th e r e t a i ne d a us t e ni t e can he lp toim pr o v e th e to u gh n e s s of th e T BM di s c cut t e r ri n g m a te r i a ls.