ESTABLISHMENT OF THE MECHANICAL
CHARACTERISTICS OF THE DEPOSITED METAL

SYMBOLS

* Tensile strength:     Rm             * Resilience........... : K
* Yield point 0,2% :   Rp (0,2)     * Toughness........... : H
* Elongation:              A

1. TENSILE STRENGTH, YIELD POINT AND ELONGATION
TENSILE STRENGTH TEST OF THE STEEL (NF A 03-151)

TEST PREMISES

This test involves subjecting a test-tube to a tensile strength until it breaks in order to determine the mechanical characteristics of the metal.

TEST-TUBES

Cylindrical section of the tube for a deposited metal: S (mm2)
Rectangular section of the tube for joint: S (mm2)


TENSILE STRENGTH TEST PREMISES

The tube that is subject to an increasing and rectangular stress extends uniformly (elastic elongation) until a certain characteristic value. This value is the tensile strength. If that stress was stopped at that point, the tube would recover its original dimensions. However, if the stress gets harder, the elongation of the tube will be faster and more pronounced until the elongation becomes permanent and the tube breaks.

This test allows us to define three important features of all metals:

* Tensile strength Rm
* Yield point:: Rp 0,2
* Elongation: A %

TENSILE BREAKING STRESS OR TENSILE STRENGTH

It is the value that shows how resistant a material is to a tensile strength:

Rm (Mpa) = F (N)  / S (mm2)

YIELD POINT

This value explains how difficultly or easily a material can elongate:

Rp0,2 (Mpa) = F (N)  / S (mm2)

ELONGATION

Difference between the original dimensions of the test-tube and its dimensions after breaking. Value expressed in %.

MEASUREMENT UNITS

Characteristics Before Now Conversion
Rm Kg/mm2 Mpa 1 Mpa = 1 N/mm2 = 0,102 Kg/mm2
Rp 0,2 Kg/mm2 Mpa 1 Mpa = 1 N/mm2 = 0,102 Kg/mm2

Mpa = Mega pascal
N = Newton

2. RESILIENCE TEST (NF A 03-156)

DEFINITION

This test allows us to check how resistante to fatigue a material is.

Resilience= energy absorved during the break (joules) / Surface S0 (cm2)

Symbol Name Test-tubes Observations
KCU Resilience (U notch)  
KCV Charpy resilience (V notch) Used at temperatures lower than 0ºC

MEASUREMENT UNITS

 

Characteristics Before Now Conversion
KCU Kg/cm2 daJ/cm2 1 daJ/cm2 = 1,02 Kg/cm2
KCV Kg/cm2 daJ/cm2 1 daJ/cm2 = 1,02 Kg/cm2

1 daJ = 10 Julios

3. TOUGHNESS TEST

DEFINITION

The toughness of a material is seen in its resistance to being penetrated by a tough object. There is a relation between the tensile strength of a metal (Rm) and its toughness.

DIFFERENT TOUGHNESS TESTS

CORRESPONDENCE OF THE MAIN TOUGHNESS UNITS

Brinell HB
P = 30 D2
Rockwel
HRB  HRC
Vickers HV
P = 294 N
(30 Kgf/mm2)
Resistencia Rm
MPa (Kgf/mm2)

80
85
90
95
100
105
110
115
120

36,4
42,4
47,4
52,0
56,4
60,0
63,4
66,4
69,4

80
85
90
95
100
105
110
115
120

270 (28)
290 (30)
310 (32)
320 (33)
340 (35)
360 (37)
380 (39)
390 (40)
410 (42)

Brinell HB
P = 30 D2
Rockwel
HRB  HRC
Vickers HV
P = 294 N
(30 Kgf/mm2)
Resistencia Rm
MPa (Kgf/mm2)

125
130
135
140
145
150
155
160
165

72,0
74,4
76,4
78,4
80,4
82,2
83,8
85,4
86,8

125
130
135
140
145
150
155
160
165

420 (43)
440 (45)
460 (47)
470 (48)
490 (50)
500 (51)
520 (53)
 

 

CORRESPONDENCIA DE LAS PRINCIPALES MEDIDAS DE DUREZA

HB
P = 30 D2
Rockwel
HRB  HRC
Vickers HV
P = 294 N
(30 Kgf/mm2)
Resistencia Rm
MPa (Kgf/mm2)

170
175
180
185
190
195
200
205
210
215
220
225
230
235
240
245
250
255
260
265
270
275
280
285
290
295
300
310
320
330
340
350
359
368
376
385
392

88,2
89,6
90,8
91,8
93,0
94,0
95,0
95,8
96,6
97,6
98,2
99,0

19,2
20,2
21,2
22,1
23,0
23,8
24,6
25,4
26,2
26,9
27,6
28,3
29,0
29,6
30,3
31,5
32,7
33,8
34,9
36,0
37,0
38,0
38,9
39,8
40,7

170
175
180
185
190
195
200
205
210
215
220
225
230
235
240
245
250
255
260
265
270
275
280
285
290
295
300
310
320
330
340
350
360
370
380
390
400

570 (58)
590 (60)
610 (62)
620 (63)
640 (65)
660 (67)
670 (68)
690 (70)
710 (72)
720 (73)
740 (75)
760 (77)
760 (78)
780 (80)
800 (82)
820 (84)
830 (85)
850 (87)
870 (89)
880 (90)
900 (92)
920 (94)
940 (96)
950 (97)
970 (99)
990 (101)
1010 (103)
1040 (106)
1080 (110)
1110 (113)
1150 (117)
1180 (120)
1210 (123)
1240 (126)
1270 (129)
1290 (132)
1320 (135)

Brinell HB
P = 30 D2
Rockwel
HRB  HRC
Vickers HV
P = 294 N
(30 Kgf/mm2)
Resistencia Rm
MPa (Kgf/mm2)

400
408
415
423
430

41,5
42,4
43,2
44,0
44,8
45,5
46,3
47,0
47,7
48,3
49,0
49,7
50,3
50,9
51,5
52,1
52,8
53,3
53,8
54,4
54,9
55,4
55,9
56,4
56,9
57,4
57,9
58,5
58,9
59,3
60,2
61,1
61,9
62,8
63,5
64,3
65,0
65,7
66,3
66,9
67,5
68,0

410
420
430
440
450
460
470
480
490
500
510
520
530
540
550
560
570
580
590
600
610
620
630
640
650
660
670
680
690
700
720
740
760
780
800
820
840
860
880
900
920
940

1350 (138)
1380 (141)
1410 (144)
1430 (146)
 

Según la Euronorma 8.55.

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