Assessing the Notch Sensitivity of High Strength Wires

Bandeira, Carlos Filipe Cardoso; Kenedi, Paulo Pedro; Souza, Luis Felipe Guimarães de

doi:10.1590/1679-78253728

Carlos Filipe Cardoso Bandeira

PPEMM - Programa de Pós-Graduação em Engenharia Mecânica e Tecnologia de Materiais, CEFET/RJ - Av. Maracanã, 229 - Maracanã - RJ - CEP 20271-110 - Brazil. fillypebandeira@hotmail.com, paulo.kenedi@cefet-rj.br, luis.felipe@cefet-rj.br

Paulo Pedro Kenedi ^** Corresponding Author

PPEMM - Programa de Pós-Graduação em Engenharia Mecânica e Tecnologia de Materiais, CEFET/RJ - Av. Maracanã, 229 - Maracanã - RJ - CEP 20271-110 - Brazil. fillypebandeira@hotmail.com, paulo.kenedi@cefet-rj.br, luis.felipe@cefet-rj.br

Luis Felipe Guimarães de Souza

PPEMM - Programa de Pós-Graduação em Engenharia Mecânica e Tecnologia de Materiais, CEFET/RJ - Av. Maracanã, 229 - Maracanã - RJ - CEP 20271-110 - Brazil. fillypebandeira@hotmail.com, paulo.kenedi@cefet-rj.br, luis.felipe@cefet-rj.br

* Corresponding Author

Chemical composition in weight
element	C	Si	Mn	P	S	Cr	Mo	Ni	Al
(%)	0.64	0.22	0.74	0.019	0.007	0.037	0.009	0.023	0.028

Specimen	S_y (MPa)	S_ut (MPa)	EL (%)
1	1150	1260	15.3
2	1180	1270	15.0
3	1150	1250	14.6
average	1160	1260	14.9

Test	HRC
1	34.8
2	36.0
3	35.5
average	35.4

Measurement	Ra longitudinal (μm)	Ra transversal (μm)
1	0.22	0.58
2	0.14	0.65
3	0.22	0.45
average	0.19	0.56

	Specimen	μ	σ	Fatigue Limit (%)
Common points	notched free	35.5	${\begin{matrix} - 4.5 % \\ + 4.5 % \end{matrix}$	33.9 ≤ (S _e / S _ut ) · 100 ≤ 37.1
Common points	notched	15.5	${\begin{matrix} - 4.5 % \\ + 4.5 % \end{matrix}$	14.8 ≤(S _e / S _ut ) · 100 ≤ 16.2
Up-and-down points	notched free	32.7	${\begin{matrix} - 1.1 % \\ + 1.0 % \end{matrix}$	32.3 ≤(S _e / S _ut ) · 100 ≤ 33.0
Up-and-down points	notched	12.7	${\begin{matrix} - 1.1 % \\ + 1.0 % \end{matrix}$	12.6 ≤(S _e / S _ut ) · 100 ≤ 12.8

\frac{σ_{a_eq}}{S_{u t}} = \frac{σ_{a}}{S_{u t}} \frac{1}{(1 - (\frac{1 + R}{1 - R}) \frac{σ_{a}}{S_{u t}})} \begin{matrix}  \end{matrix} or \begin{matrix}  \end{matrix} \frac{σ_{a_eq}}{S_{u t}} = \frac{(1 - R) (\frac{σ_{max}}{S_{u t}})}{(2 - (1 + R) (\frac{σ_{max}}{S_{u t}}))}

\frac{σ_{max}}{S_{u t}} = \frac{2 (\frac{σ_{a_eq}}{S_{u t}})}{((1 - R) + (1 + R) (\frac{σ_{a_eq}}{S_{u t}}))}

$(\frac{σ_{max}}{S_{ut}})$ · 100 (%)	$(\frac{σ_{a_eq}}{S_{ut}})$ · 100 (%)	number of cycles
		common set 0	up-and-down set 0	up-and-down set 1
50	31	1866774	1012461	1017371
52	32.8	-	174463	185197
54	34.6	-	1021397	166963
56	36.4	-	205270	-
60	40.3	138934	-	-
70	51.2	75026	-	-
80	64.3	44790	-	-
90	80.2	36380	-	-

$(\frac{σ_{max}}{S_{ut}})$ · 100 (%)	$(\frac{σ_{a_eq}}{S_{ut}})$ · 100 (%)	number of cycles
		common set 0	common set 1	common set 2	up-and-down set 0	up-and-down set 1	up-and-down set 2
18	9	-	-	-	1011280	-	-
21.5	11	1163500	-	-	1093159	1001769	-
24.9	13	-	-	-	1042841	344703	788188
28.2	15	-	-	-	178635	-	-
35.7	20	105162	76117	90535	-	-	-
46.4	28	47501	32698	28350	-	-	-
55.6	36	24117	20234	20420	-	-
66.3	47	16000	13501	12040	-	-	-
91	82	6141	-	-	-	-	-

\begin{array}{l} K_{1} = 0.721 + 2.394 \cdot \sqrt{h / r} - 0.127 \cdot h / r \begin{matrix}  \end{matrix} \begin{matrix}  \end{matrix} K_{2} = - 0.426 - 8.827 \cdot \sqrt{h / r} + 1.518 \cdot h / r \\ K_{3} = 2.161 + 10.968 \cdot \sqrt{h / r} - 2.455 \cdot h / r \begin{matrix}  \end{matrix} K_{4} = - 1.456 - 4.535 \cdot \sqrt{h / r} + 1.064 \cdot h / r \\ K_{t_U} = k_{U} \end{array}

[1] * Corresponding Author

Brasil

Brasil

Assessing the Notch Sensitivity of High Strength Wires

Abstract