Carburizing methods are: gas carburizing, liquid carburizing, carburizing and special carburizing solid. Special carburization typically under specific physical conditions, find application at home and abroad at present are: a high-frequency electric field heating carburizing, vacuum carburizing under vacuum, plasma carburizing under ion bombardment conditions, the electrolysis discharge conditions electrolytic carburizing, carburizing fluidized bed particles flowing state like. The main features of the carburizing process is: carburizing and nitriding compared with infiltration speed, process time is short; although lower layer hardness, brittleness but small; the diffusion layer thickness, can withstand a greater compressive stress; layer hardness gradient is small, easy to produce peeling; high strength core part, have a greater carrying capacity; low cost, economic advantages. Carburizing and carbonitriding compared layer hardness although slightly lower, but much larger than the thickness of the diffusion layer carbonitriding layer (generally less than 0.8mm), thus representing carburizing layer carbonitriding layer has a higher carrying and the ability of anti-extrusion. Carburizing and induction hardening strengthening, compared with a high surface hardness hydraulic drill rod material, good wear resistance; core part strength, high hardness, resistance to compression, flexural fatigue strength is good; not the complexity of the shape of the workpiece and batch size limit; the workpiece processing performance and good uniformity. Other chemical heat diffusion layer hexagonal hollow steel, such as boriding vapor deposition of metal and TiC, TiN, with its depth of penetration is much thinner than the hollow steel carburizing concentration gradient greater rock drill rod, either significant load carrying capacity, or the ability to resist surface brittle flakes are far less than the carburized layer. Rod for failure were analyzed and found life and hardness of heart related. In ensuring the whole cross-section of the entire drill rod hardenability (ie core part full martensite), the toughness and hardness of the drill rod has a direct relationship. Hardness depends on the chemical composition of the steel, wherein the carbon content play a decisive role. With the increase of carbon content, i.e., drill rod hardness increased strength and improved toughness. FF-710 steel, we use the carbon content of 0.24% to 0.30%, quenching and tempering hardness HRC46 ~ 52 rock drill rod hollow drill steel _ Shandong Peng Rui Technology Limited (Certified) _ hollow steel by Shandong Peng Rui Drilling Technology Limited. Drilling Ltd. Shandong Peng Rui (www.zbpengrui.com) Shandong Zibo, metal cutting class leader, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs. Shandong Peng Rui Drilling Ltd. led the staff warmly welcome all inquiries negotiations to create Shandong Peng Rui Drilling Ltd. a better future.