5. Materials for organe de asamblare fasteners

1 5. Materiale pentru organe de asamblare 5. Materials for fasteners If we consider the fasteners f rom the geometrical point of view, we can say that they are, generally, corr-ponents characterized by the presence of thread whicr is a great stress concentrator. Therefore, the steels which are to be used should ha* a minimum sensibility to the effect of these con centrators and the adequate mechanical strength a well. The standardized fasteners which operate at the en vironmental temperature are manufactured of stee having the characteristics according to table Tabelul/ Table 4. Organele de asamblare , n general, sunt piese carac-terizate din punct de vedere al configura iei geometrice, de existen a filetului, care este un puternic concentrator de tensiuni.

2 Prin urmare, o elurile care se folosesc trebuie s prezinte o sensibilitate minim la efectul acestor con-centratori, n condi iile unei rezisten e mecanice corespunz toare. Organele de asamblare standardizate, care lucreaz la temperatura mediului ambiant, sunt executate din o eluri care ndeplinesc condi iile din tabelul Clasa de calitate( uruburi)/ Property class [screws and boite) Caracteristici/Characteristics Unitatea de m sur / Unit of measure ^.8 d<16 d >6 Rezistenta de rupere la trac iune/ Tensile strenqth Rm min. N/mm2 330 400 420 500 520 600 800 830 1220 Limita de curgere aparent / Apparent yield stress Re min. N/mm2 190 240 340 300 420 480 - - Limita de curgere conven ional / Stress at permanent set limit RDo 2 - - - - - - 640 660 940 1100 Alungirea la rupere/ Elongation after fracture AS min.]

3 % 25 22 14 20 10 8 12 12 9 8 Categorii de o el recomandate/ Recommended types of steel - A A A, B A, B A, B A, B B, C D, E D, E E Starea materialului n produsul finit/ Material condition in the finished product - F r tratament termic/ Without heat treatment. Cu tratament termic/ With heat treatment. A - o el carbon de uz general/ Carbon steel of general use B - o el pentru prelucr ri pe ma ini-unelte automate/ Free-cutting steel C - o el carbon de calitate/ Carbon steel D - o el cu Mn ( ,4%) i B(0, ,005%)/ Steel alloyed with Mn ( ,4%) and B ( ,005%) E - o el aliat/ Alloyed steel Pentru cele nestandardizate, dac se specific n co-mand sau n documenta ia tehnic clasa de calitate, se pot folosi acelea i categorii de o eluri, alegerea materialului fiind la latitudinea produc torului.

4 Atunci c nd se impune materialul i nu clasa de calitate, se pot folosi i alte m rci de o eluri sau aliaje neferoase, n concordan cu documenta ia tehnic . n cazul organelor de asamblare tratate termic se recomand ca dup c lire structura n miezul p r ii filetate s con in aproximativ 90% martensit . La uruburi, prin tratamentul termic se urm re te ar- in case of non-standardized fasteners , if the propert> class is specified in the order or technical documenta-tion, the same types of steels can be used, at the producer's choice. When the material is specified but not the property class, other types of steels or non-ferrous alloys can be used, according to the technical documentation. In case of heat treated fasteners , it is recommendec that after hardening, the structura in the core of tN threaded portion should contain about 90% martensite By accomplishing the heat treatments of screws and monizarea ntre caracteristicile de rezisten i sen-sibilitatea la concentratori.

5 Qre terea rezisten ei la oboseal se realizeaz prin aplicarea unor tehnologii de fabrica ie adecvate - deformare plastic la rece, rularea filetului etc. O elurile destinate fabric rii de organe de asamblare - deformare plastic la rece sunt reglementate prin STAS 9382/1 i sunt prezentate n tabelul : bolts, one can nave in view the harmonization of the strength characteristics and sensibility to concentrators. The fatigue strength can be increased by using proper manufacturing technologies - plastic cold deformation, thread rolling etc. The steels intended to fasteners manufacturing by plastic cold deformation are stated in STAS 9382/1 and are listed in table : Tabelul/Table Marca otelului/ Steel symbol Sleirea de livrare/ Delivery condition * OL34q OL37q L,C,T,TR,RTRT,CT,TS RCB52q L,T,TR,CTR OLCIOq OLC15q 15Cr9q 18 MnCM1q 18 MoCrNi13q 13 CrNi30q 21 MoMnCr12g LR,TR,CTR,TRS OLC22Bq 19 BMn10q 20 BMn13q 20 BCrMn13q LR,TR,CTR,TRS,CT OLC25q OLC35q OLC45q 36 BMn11q 36 BCrMn11q 40Cr10q 40 BCr10q 40 CrNi12q 34 MoCr11q 42 MoCr11q 34 MoCrNi16q 30 MoCrNi20q LR,TR, ,CT,TS * L - laminat/ rolled steel C - cojit/ peeled steel T - tras/ stretched steel R - recopt/ annealed steel S - lefuit/ round steel O elurile netratate care se folosesc pentru organe de asamblare ob inute prin deformare plastic la rece sunt prezentate n tabelul i tabelul.

6 The not-heat treated steels which are used for faster processed by plastic cold deformation are listed in 1 and table : Tabelul /Table Compozi ia chimic / Chemical composition, % 1 Marca o elului/ Steel symbol C Mn P max S max Si max Cr Ni max Cu Al N2 max V max OL34q ,15 0,20 -0,55 0,050 0,050 0,07 - - - - |OL37q 0,10-0,17 0,25-0,45 0,040 0,040 0,07 ,20 0,20 ,20 0,007 RCB52q ,18 ,15 0,040 0,040 0,06 0,50-0,80 - 0,30-0,60 ,025 0,015 0,12 Tabelul/Table Caracteristici mecanice/ Mechanical characteristics Marca otelului/ Steel symbol Stare de livrare/ Delivery condition * Rezistenta la rupere/ Tensile strength, Rm, N/mm2, max. Alungirea la rupere/ Elongation after fracture Ag, %, min.

7 G tuirea la rupere/ Rupture constriction, Z, %, min. j L, C 60 T,CT,RTRT,TS 58 OL34q TR 420 9 65 L, C 440 60 T,CT,RTRT,TS 470 59 OL37q TR 430 8 63 L 610 50 T,TR 630 48 RCB52q CTR 550 60 * L - laminat/ rolled steel C - cojit/ peeled steel T - tras/ stretched steel R - recopt/ S - lefuit/ round steel O elurile de cementare destinate fabric rii organelor de asamblare prin deformare plastic la rece produse n ara noastr sunt prezentate n tabelul i tabelul : The case-hardening steels intended to the manufactur-ing of the fasteners by plastic cold deformatior produced in Rom nia are listed in table and table Tabelul/Table Compozi ia chimic / Chemical composition, % Marca o elului/ Steel symbol C Mn S max P max Cr Ni Mo OLCIOq 0,07-0,14 0,35-0,65 0,040 0,045 - - OLC15q 0,12-0,18 0,35-0,65 0,040 0,045 - 15Cr9q 0,12-0,18 0,40-0,70 0,035 0,035 0,70-1,0 - 18 MnCr11q 0,15-0,21 0,90-1,20 0,035 0,035 0,90-1,20 - 17 MoCrNi14q 0,14-0,20 0,60-0,90 0,035 0,035 0,85-1,15 1,20-1,60 0,15-0,25 13 CrNi30q 0,09-0,16 0,30-0,60 0,035 0,035 0,60-0,90 2,75-3,15 21 Moi' Cr12q 0,18-0,24 0,80-1,20 0,035 0,035 1,00-1,40 0,20-0.

8 30 Tabelul/Tabel Marca o elului/ Caracteristici mecanice/Mechanical characteristics Steel symbol Diametrul Felul trata- Limita de Rezisten a la Alungirea la G tuirea la Rezilien a/ probei de mentului curgere/ rupere/ rupere/ rupere/ Impact tratament termic/ Type Yield stress, Tensile Elongation Rupture strength termic de of heat RP .2, strength, after fracture constriction, KCU 300/2, referin / treatment * N/mm2 Rm, N/mm2 A5, % Z, % J/cm2, min. Diameter ofmm. mm. mm. the sample for r ference eheat treatment, mm OLC10** 11 Cr 390 790 13 30 290 640 16 - - OLC15q** 11 440 880 12 35 30 330 .780 14 45 - 15Cr9q 15 495 12 45 69 18 MnCr11q 15 735 10 40 - 17 MoCrNi14q 16 850 1200..1550 8 50 13 CrNi30q 15 690 11 55 21 MoNnCr12q 16 830 8 40 68 *- C - c lire/ hardening; r - revenire joas / low temperature tempering ** - Pentru produsele cu diametre (grosimi) sub 30 mm, se iau probe de tratament termic cu diametrul de 11 mm, ar pentru produsele cu diametre (grosimi) de 30 mm i peste se iau probe cu diametrul de 30 mm/ - For products with diameters (thickness) smaller than 30 mm, the diameter of the samples for heat treatment hould be of 11 mm and for products with diameters (thickness) equal to and larger than 30 mm, the sample liameter should be of 30 mm.

9 O eluri de cementare elaborate n alte ri, tabelul i tabelul : GERMANIA Case hardening steels manufactured in other countries -table and table : GERMANY Tabelul/Table Compozi ia chimic / Chemical composition, ' Steel symbol C Mn S max P max Cr Ni Mo C10 0,07-0,13 0,30-0,60 0,045 0,045 - C15 0,12-0,18 0,30-0,60 0,045 0,045 .. 16 MnCr5 0,14-0,19 1 ,0-1 ,30 0,035 0,035 0,80-1,10 - SUA USA Tabelul/Table Compozi ia chimic / Chemical om cposition, %Marca o elului/ Steel symbol C Mn S max P maxCr Ni Mo 5115 0,13-0,18 0,70-0,90 0,040 0,035 0,70-0,90 - Marca o elului/ O elurile de mbun t ire recomandate pentru prelucrarea prin deformare plastic la rece n fabrica ia organelor de asamblare produse n ara noastr sunt prezentate n tabelul i n tabelul.

10 The hardening and tempering steels recommendec manufacturing by plastic cold deformation of the * teners in Rom nia are listed in table and table 4 Tabelul/Table Compozi ia chimic / Chemical composition, % Marca o elului/ Steel symbol C Mn Si P max S max Cr Ni Mo B Ti OLC25q 0,22-0,29 0,40-0,70 0,17-0,37 0,035 0,035 - - - - - OLC35q 0,32-0,39 0,50-0,80 0,17-0,37 0,0350,035 - - - - OLC45q 0,42-0,50 0,50-0,80 0,17-0,37 0,035 0,035 - - - - - OLC22Bq* 0,19-0,25 0,50-0,80 0,17-0,37 0,0350,035 - - - 0,0008-0,005 0,01-0 :*19 BMn10q* 0,80-1,20 max. 0,250,0350,035 - - - 0,002-0,005 0,01-0 >20 BMn13q* 0,17-0,23 1,10-1,40 0,15-0,40 0,035 0,035 - - 0,003-0,005 0,01-0 :*36 BMn11q* 0,34-0,40 0,90-1,20 0,17-0,37 0,035 0,035 - - 0,003-0,005 0,01-0 >20 BCrMn13q* 0,17-0,23 1,10-1,40 0,10-0,40 0,035 0,035 0,20-0,45 - - 0,003-0,005 :*36 BCrMn11q* 0,34-0,40 0,90-1,20 0,17-0,37 0,035 0,035 0,20-0,45 - - 0,003-0,005 0,01-0.