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Welding
of
Tool
Steel
and
Carbon
Steels |
Welding
of
Tool
Steel
and
Carbon
Steels -
Welding of Tool Steel
Tools steels range from plain carbon steels (C 1.41.5%) to high alloy high speed steels, some of which have a total alloy content that exceeds 25%.
Given below are the typical compositions (%) of a few tool steels
(i) W-high speed steel
C 0.75, Cr 4, V 1, W 18, Co 5
(ii) Mo-high speed steel
C 0.8,Cr 4, V 1.5, W 4, Mo 5, Co 12
(iii) High C High Cr Steel
C 1.5, Cr 12, Mo.1, Co 3
(iv) Air hardening steel
C 2.25, Cr 5.25, V 4.75, W 1, Mo 1
(v) Oil hardening steel
C 0.9, Mn 1, Cr 0.5, W 0.5
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(vi) Water hardening steel
C 0.6/1.4, V 0.25
(vii) Hot work steel
C 0.4, Cr 3.25, V 0.4, Mo 2.5
(viii) Shock resisting steel
C 0.5, Cr 3.25, Mo 1.4
Welding of Carbon Steels
Carbon steels differ from cast iron as regards the percentage of carbon. They contain carbon from 0.10 to 1.5% whereas cast iron possesses carbon from 2.0 to 4.2%.
Carbon steels are classified as
Low carbon steels - C 0.05-30%
Medium carbon steels - C 0.30-50%
High carbon steels - C 0.50-5%
Carbon steels find uses as follows:
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Low carbon steel
0.05-15% C - Rivets, screws, press sheets, pipe, nail and chain
0.15-30% C - Plates, structural shapes and bars.
Medium carbon steel
0.30 - 50% C - Shafts, axles, connecting rods.
High carbon steel
0.50 - 0.75% C - Crankshaft, scraper blades, automobile springs, anvils, band saws, etc.
0.75 - 0.90% C - Punches and chisels.
0.90 - 1.0% C - Shear blades and knives.
1.00 - 1.2% C - Taps, dies, milling cutters, lathe tools, etc.
1.20 - 1.3% C - Reamers and files.
1.30 - 1.5% C - Wire drawing dies and metal cutting saws.
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