HS 21(Co-Cr-Mo)

1. Introduce

– HS : Abbreviation for Haynes Stellite

– Developed as a corrosion-resistant CoCr(Mo) alloy

– Applied as a biocompatible hip implant and denture alloy

– Most of the alloys currently used in medical applications are variations of HS 21

– Consists of a CoCrMo alloy base containing dispersed hard carbides that strengthen the alloy and increase hardness but decrease ductility

– Oxidation and reduction resistance up to a temperature range of 1150°C

– UNS R30021, W73041, W73021

* Stellite Alloys

1. A Co-Cr alloy designed for wear resistance
2. Alloys with Cr, C, W, Mo, etc. added to a Co base
3. Excellent corrosion, erosion, and wear resistance
   → Cause : Intrinsic properties of hard carbide phase dispersed in the CoCr alloy base

* UNS

1. Abbreviation for Unified Numbering Systems for Metals and Alloys
2. Unified unique numbering system for metals and alloys
3. A representative number that is compatible with metals and alloys defined in many material-related codes such as ASTM, AISI, ASME, AWS, etc.

* R : Reactive and Refractory Metals and Alloys

* UNS R30021 : 3XXXX : Cobalt

* W : Welding Filler Metals Classified by Weld Deposit

* UNS W73041, W73021 : 7XXXX : Surfacing Alloys

2. Property

– Good strength, hardness, abrasion resistance, heat and mechanical shock resistance

[HS 21 Chemical Composition (%)]

[HS 21 Mechanical Properties]

[HS 21 Physical Properties]

3. Standard & Specification

– Specification : UNS W73041, W73021

4. Available Form

– Plate, Sheet

– Bar, Rod

– Coil, Strip

– Pipe, Tube

5. Application & Product

– Medical, Aerospace

(1) Hip implants / (2) Surgical equipment / (3) Jet engines / (4) Molds