Hardening Hardness

Case wear rings No Cast iron Bronze Cast iron Ni-resist Cast iron 12% CHR 12% CHR Hard Faced 316 AUS (3) Monel 12% CHR hardened Hard Faced AUS (3) Hard Faced 316 AUS (3) Duplex (3)... 

Case Wear Rings No Cast Iron Bronze Cast Iron Ni-Resist Cast Iron 12%CHR Hardened 12% CHR Hardened Hard-faced 316AUS6 N-Cu Alloy 12% CHR Hardened Hard-faced AUSe Hard-faced 316 AUS e Hard-faced Duplex Hard-faced Super Duplex ... 

Hardener hard-n9r (1611) n. Additive (cross-linking agent, resin, or other modifier) used to promote or control the hardening or curing reaction of a coating, plastic, adhesive or resin system. G Harter m, F durcisseur m, S endurecedor m, I induritore m. Odian GC (2004) Principles... 

As deposited, the microhardness of electroless nickel-phosphorus coating is about 5(X) to 600 HVN (48-50 HRC), equivalent to many hardened steels. After precipitation hardening, hardness values as high as 1100 HVN are reported, which is equivalent to commercial hard-chromium... 

Chromium is used to harden steel, to manufacture stainless steel, and to form many useful alloys. Much is used in plating to produce a hard, beautiful surface and to prevent corrosion. Chromium gives glass an emerald green color and is widely used as a catalyst. 

Ruthenium is a hard, white metal and has four crystal modifications. It does not tarnish at room temperatures, but oxidizes explosively. It is attacked by halogens, hydroxides, etc. Ruthenium can be plated by electrodeposition or by thermal decomposition methods. The metal is one of the most effective hardeners for platinum and palladium, and is alloyed with these metals to make electrical contacts for severe wear resistance. A ruthenium-molybdenum alloy is said to be... 

Hardboards Hard coals Hardcoats Hard copy systems Hardenability Hardened fatty acid Hardeners... 

A hardness indentation causes both elastic and plastic deformations which activate certain strengthening mechanisms in metals. Dislocations created by the deformation result in strain hardening of metals. Thus the indentation hardness test, which is a measure of resistance to deformation, is affected by the rate of strain hardening. 

The principle of the Brinell hardness test is that the spherical surface area of a recovered indentation made with a standard hardened steel ball under specific load is direcdy related to the property called hardness. In the following, HBN = Brinell hardness number, P = load in kgf,... 

In the Rockwed test a spheroconical diamond (Brale) indenter or a hardened steel bad is used with various load ranges to achieve a series of scales identified by a suffix letter (Table 3). The suffix letter defines both load and indenter. The most popular scales used are "C" for hard materials and "B" for soft materials. A Rockwed hardness number is meaningless without the letter suffix, eg, HRC 54 or HRB 95. 

Hardness, Impact Strength. Microhardness profiles on sections from explosion-bonded materials show the effect of strain hardening on the metals in the composite (see Hardness). Figure 8 Ulustrates the effect of cladding a strain-hardening austenitic stainless steel to a carbon steel. The austenitic stainless steel is hardened adjacent to the weld interface by explosion welding, whereas the carbon steel is not hardened to a great extent. 

Fig. 9. Microhardness profiles across interface of explosion-clad age-hardenable aluminum alloy 2014-T3 where the initial hardness is shown as Q (a) low,...

Steel Surface hardness, HRC Method of hardening Number of shafts tested Cycles to failure x 10 ... 

Because the time at high temperature is much less, austenite is produced, which is chemically inhomogeneous especially with undissolved carbides, and has a fine grain crystal size. The formation of the hard martensite requites more rapid cooling than for conventional hardening. Thus case hardening by heat treatment intrinsically requites that the surface region to be hardened be relatively thin and cooled rapidly. 

Fig. 3. Flame hardening (a) tempeiatuie—time heating curves of a 25 x 50 x 100 mm specimen at a feed of 75 mm /min and burner distance of 8 mm showing temperatures of A, surface B, 2 mm below surface and C, 10 mm below surface (b) hardness—depth curves for a 0.50% C steel 25 X 75 X 100 mm specimen at a feed of 50 mm /min, temperatures ia °C measured 10 mm below the surface, and burner distances ia mm, respectively, of A, 530 and 50 B, 540 and 12 C, 545 and 10 D, 550 and 8 and E, 565 and 6. Flame heating followed by water spray quenching. HV = Vickers hardness.

Typical hardness distribution curves obtained by induction hardening are available (5). Case depths of ca 0.05—0.5 cm are commonly obtained. 

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