Steel carburizing

Fig. 9. Effect on fatigue strength of the plastic deformation of a carburized steel surface by shot peening (B) as compared to nitriding (A) and heat treating...

Many steels used for gears and bearings are surface-hardened by carburizing, quenching, and tempering. Molybdenum is frequendy used in carburized steels, and carburized Ni—Mo steels have been shown to provide optimum resistance to fatigue and impact effects (28). 

Carbides Steel, nitriding Steel, carburizing Steel, water-hardening Steel, oil-hardening Steel, air-hardening Nickel, cobalt alloy Steel, prehardened 44 Rc Beryllium, copper Steel, prehardened 28 Rc Aluminum bronze Steel, low alloy 6t carbon Kirksite (zinc alloy) Aluminum, alloy Brass... 

HI Thompson Fiber Glass Co., Graphite cloth aids carburizing. Steel, 155, No. 14, 100, 1964. 

The principal mold steels are the P-type mold steels as specified by the American Iron and Steel Institute, specifically P6, a carburizing steel having moderate hardenability P20, also with moderate hardenability and P21, a deep-hardening steel. 

Low-carbon steel can be hardened in order to improve the wear resistance by carburizing. Steel is carburized by exposing it to gas, liquid, or solid, which provides a high carbon concentration at the surface. Given the percentage carbon versus depth graphs for various times at 930°C, how can the diffusion coefficient be estimated from the graphs ... 

Figure 9.7 shows the hardness and modulus distributions of the MoDTC/ZDDP and ZDDP tribofilms, carburized steel disc, and fused silica as a function of the contact depth [1]. Since the fused silica as the standard sample for tip-shape calibration retained constant hardness and modulus values in a contact depth range from 5 nm, the hardness and modulus of the tribofilms were examined at contact depths greater than 5 nm. It was found that both kinds of tribofilms had the same hardness and modulus distributions relative to the contact depth. When the contact depth was greater than 30-40 nm, the mechanical properties were constant, with hardness staying at the fused silica level of 10 GPa and the modulus at the carburized disc level of 215 GPa. However, when the contact depth was reduced from 30 nm to 5 nm near the film surface, film hardness decreased from the fused silica level of 10 GPa to 6 GPa, and the modulus decreased from the carburized steel level of 215 GPa to 150 GPa. 

The treatment conditions are the same as those in Fig. 7. The electrochemical test results for Hybrid-NCT, Nitriding-NT, Carburizing-CT were described in Fig. 12 The NT and CT showing that the current density of treated stainless steel were decreased in the anodic region which indicating positive effect regarding the improvement of corrosion resistance compared to the substrate. After Hybrid-NCT treatment, the anodic pwlarization curved is shifted towards lower current density which explain that the corrosion rate was decreased and the polarization current measurement gave 0.00003 mA/ cm and demonstrate an improvement in corrosion resistance as compared to that untreated and individually nitrided and carburized steel, while passivation current of NCT is the lowest followed by CT, NT and untreated respectively. This trend also similar to the maximum potential passivation behaviour since the... 

High-Temperature Corrosion on carburized steels that forms a porous scale of several iron oxide phases. 

Low alloy carburizing steels wrought, quenched tempered 178 (1227) 62 (427)... 

M Carburized steel Nitrided low-alloy steel Unlubricaled through-hardeoed steel Glass-filled PTFE... 

Fig. 3.63 S-N diagram for shot-peened and not shot-peened carburized steel (modified Irom [62])...

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