MRC MH180 - Page 19

Table 2
No. Material HLD Strength σ
b
(MPa)
1 Mild steel 350～522 374～780
2 High-Carbon steel 500～710 737～1670
3 Cr steel 500～730 707～1829
4 Cr-V steel 500～750 704～1980
5 Cr-Ni steel 500～750 763～2007
6 Cr-Mo steel 500～738 721～1875
7 Cr-Ni-Mo steel 540～738 844～1933
8 Cr-Mn-Si steel 500～750 755～1993
9 Super strength steel 630～800 1180～2652
10 Stainless steel 500～710 703～1676
Table 3
Type of impact device DC(D)/DL D+15 C G E
Impacting energy
Mass of impact body
11mJ
5.5g/7.2g
11mJ
7.8g
2.7mJ
3.0g
90mJ
20.0g
11mJ
5.5g
Test tip hardness:
Dia. Test tip:
Material of test tip:
1600HV
3mm
Tungsten
carbide
1600HV
3mm
Tungsten
carbide
1600HV
3mm
Tungsten
carbide
1600HV
5mm
Tungsten
carbide
5000HV
3mm
synthetic
diamond
Impact device diameter:
Impact device length:
Impact device weight:
20mm
86(147)/
75mm
50g
20mm
162mm
80g
20mm
141mm
75g
30mm
254mm
250g
20mm
155mm
80g
Max. hardness of
sample
940HV 940HV 1000HV 650HB 1200HV
Mean roughness value
of sample surface Ra:
1.6μm 1.6μm 0.4μm 6.3μm 1.6μm
Min. weight of sample:
Measure directly
Need support firmly
Need coupling tightly
>5kg
2～5kg
0.05～
2kg
>5kg
2～5kg
0.05～2kg
>1.5kg
0.5～1.5kg
0.02～0.5kg
>15kg
5～15kg
0.5～5kg
>5kg
2～5kg
0.05～2kg
Min. thickness of sample
Coupling tightly
Min. layer thickness for
5mm 5mm 1mm 10mm 5mm
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