Rotary Digging Teeth3050

Pick for rotary drilling rig is a consumable part in coal mining and tunneling machinery, serving as the primary tool for dropping and crushing coal. Its performance directly impacts the mining machinery’s production capacity, power consumption, operational stability, and the service life of other related components.

 

Common Materials

[Common Materials for Pick for Fotary Drilling Rig]

When cutting coal and rock, picks are subjected to high cyclic compressive stress, shear stress, and impact loads. Although coal is not very hard, it often encounters hard materials such as gangue. Friction and impact during the coal and rock cutting process also cause the pick to heat up. Operating under such complex working conditions, the pick body must be both wear-resistant and impact-resistant. The pick body is generally made of low-alloy structural steel.

[42CrMo Steel] features high strength, high hardenability, good toughness, minimal quenching deformation, and high creep and endurance strength at high temperatures. After heat treatment, 42CrMo steel exhibits a high fatigue limit and resistance to multiple impacts, as well as good low-temperature impact toughness.

[35CrMnSi steel] is also a material with excellent hardenability. After proper heat treatment, it can achieve excellent combined mechanical properties of strength, hardness, toughness, and fatigue strength, making it suitable for complex coal mining conditions.

[Si-Mn-Mo meta-bainitic steel] is a new type of pick cutter body material developed by domestic research institutions. Its distinguishing feature is its rationally designed alloy composition, which allows for excellent heat treatment performance. After heat treatment, the steel’s strength, toughness, and wear resistance meet the mechanical performance requirements of pick cutters.

There are many other steel grades suitable for pick cutter operating conditions. During pick manufacturing, the appropriate pick cutter body material can be selected based on the pick type and specific operating conditions.

 

Heat Treatment Process

[Pick for Heat Treatment Process in Fotary Drilling Rig Production]

The conventional heat treatment process for 42CrMo cutter bodies is: oil quenching at 840°C followed by tempering at 360-400°C. The conventional heat treatment process for 35CrMnSi tool bodies is: oil quenching at 880°C followed by tempering at 380-430°C. Manufacturers with the necessary conditions may also employ a heat treatment process consisting of heating and holding at 880°C followed by austempering at 280-320°C, followed by air cooling.

 

Si-Mn-Mo meta-bainitic steels utilize an 880°C normalizing followed by tempering. This heat treatment results in a meta-bainitic structure composed of bainite, ferrite, and retained austenite, offering a good balance of strength and toughness, as well as high wear resistance.