30CrMo 4130 25CrMo4 SCM430

30CrMo Gear Steel Bar

30CrMo gear steel has high strength and toughness, high hardenability, the critical hardenability diameter in oil is 15～70mm; the thermal strength of steel is also good, it has sufficient high temperature strength below 500℃, but at 550℃ Its strength is significantly reduced; when the alloying element is at the lower limit, the welding is quite good, but when it is close to the upper limit, the weldability is medium, and it needs to be preheated to above 175℃ before welding; the machinability of steel is good, and the plasticity during cold deformation is medium; The range of 300～350℃ has the first type of temper brittleness; there is a tendency to form white spots.

30CrMo gear steel is usually used in the quenched and tempered state. When the carbon content is lower, it can also be used as a carburizing steel that requires a higher core strength. In the medium-sized machinery manufacturing industry, it is mainly used to manufacture quenched and tempered parts with large cross-sections and working under high stress conditions, such as shafts, spindles, and high-load control wheels, bolts, studs, gears, etc.; in the chemical industry Used to manufacture welded parts, welded structures composed of plates and pipes, and high-pressure pipes that work in a nitrogen-hydrogen medium with a temperature not exceeding 250°C; used in the manufacturing of steam turbines and boilers to make fasteners that work below 450°C, Flanges and nuts subject to high pressure below 500°C are especially suitable for the manufacture of pipes that work at 300 atmospheres and below 400°C.

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30CrMo Equivalent Grade: