Carbon steels flame hardening

PISTON RINGS are normally cast-iron of the single-piece snap-ring type, although other materials may be used when conditions require. PISTON ROD is carbon-steel, flame-hardened over packing travel area. 

PISTON ROD is carbon-steel, flame-hardened over packing travel area unless otherwise specified. 

The dies themselves are generally constructed of medium carbon alloy steels, with flame-hardened lips and chrome or nickel plating on the flow surfaces. Insulation of the die body Is common to prevent temperature variations that could result from air drafts. Dies can be electrically heated, or steam or oil heat can be used. Cooling is usually provided by natural convection, though forced air can also be used. 

The flame-hardening process is used for a wide variety of applications. These include (1) parts that are so large that conventional furnace treatments are impractical or uneconomical, (2) prevention of detrimental treatment of the entire component when only small segments of die part require heat treatment, and (3) use of less costly material to obtain the desired surface properties where alloyed steels would be normally applied. Flame hardening is limited to hardenable steels (wrought or cast) and cast iron. Typical hardnesses obtained for the flame-hardened grades depend on the quench media (Table 1). The practical level of minimum surface hardness attainable with water quenching for various carbon contents is shown in Fig. 1. 

Local surface hardening, for example, flame, induction, or laser for medium-carbon steels... 

For medium-carbon steel parts, consider the surface treatments listed above for mild steels, plus local surface hardening, for example, flame, induction, or laser for maximum loading, and for large rolling components (e.g., large cylindrical roller bearings and tracks). 

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