Material Choices for Oval liner and Screw Element

  • CPM-9V material which is made by Crucible Particle Metallurgy is one choice, but it is expensive, and it takes longer to ship.

  • For high-wear resistant screw elements, the material is usually processed with HSS (high speed steel), Chinese name is W6Mo5Cr4V2, American name is AISI: M2. HSS is one kind of alloy tool steel. Its main component is W, Mo,Cr, V, Si, Mn, all the alloy element is up to around 10~25%, after vacuum hardening, its HRC is over 60 even when working at 500℃. It is used to manufacture wear-resistant tools, die and segment elements, e.g. high grade trimming dies, screw dies, hobs, saw blades, etc.

  • To manufacture ellipse ovalliners inside the segment barrel, we use PM-HIP technology. The Ω 101A alloy is produced according to W&P Company requirements and its hardness is HRC 58~64. PM-HIP material is very similar to CPM material, its hardness and main elements are listed below:

    Alloy Base HRC Wear resistance Corrosion resistance Thermal expansion Alloy elements (Weight:%)
    Ω101A Fe 60~64 ★★★★ 12.6 Cr:20 V:8 C:2.5
    Ω201A Co 52~54 ★★ ★★★★ 11.9 Cr:29 W:13 C:2.2
    Ω301A Co 58~60 ★★★ ★★★★ 10.5 Cr:33 W:18 C:2.5

  • Compareed with contact wear ration between two kinds of metal, generally say the elements made by same metal, this contact wear ratio is the worst. Such as if to use CPM segment elements match to our Ω101A ovalliner, then its service life is not longer than in this case that HSS segment elements match to our Ω101A ovalliner. A try will convince you!

  • For corrosion resistant screw element, we could choose the material such as 00Cr17Ni14Mo2, also named as 316L in USA. For example, our quotation of OD 30 screw element, every mm in length is about Euro 9.20. But the total weight of raw material for making this spec product in one order should be over 200kg.

  • To get more corrosion resistance, there are three corrosion resistant ways to be chosen, one is to get TiN (Titanium Nitride) plating layer, its color is golden brown, hardness is about HV 2000~2300, thickness is 1.2~1.5 uμ and its friction coefficient is about 0.55. Second way is to get ZrN (Zirconium Nitride) plating layer, its color is blue-green and all other data is the same as above. But we believe if to get nanometer ceramics compound coating which we are researching now and some samples are trying on customer’s machines, would be the best choice.