technical
data
12-14% Manganese
Work-Hardening Wear Resistant Steel
Standard
CREUSABRO® M / X120 Mn12 / 12-14% Manganese
A high manganese, fully austenitic, quench annealed, non magnetic, work-hardening steel with an exceptionally high level of wear resistance when subjected to work-hardening by shock or high impact pressure in service.
The main characteristics is a superior wear resistance:
Severe wear on the surface has a work-hardening effect on the austenitic structure of this steel.
This, when combined with the level of carbon in accordance with the international standards, leads
to an increase in hardness from 200BHN (in as delivered plate) up to an in-service hardness of at
least 600BHN.
This work-hardening capability renews itself through out in-service life. The underlayers not work-hardened maintain an excellent resistance to shock and a very high ductility.
Chemical Analysis Typical values (% weight)
|
C |
Si |
Mn |
S |
|
1.15 |
0.40 |
13 |
≤0.002 |
Processing
The grade is processed by usual methods taking into account its special properties: specifically its aptitude for work-hardening, high coefficient of expansion, and low thermal conductivity.
Cutting
· Thermal Cutting: possible using oxy-acetylene with iron powder addition or improved using plasma or laser cutting which result in a cleaner quality of cut.
· Mechanical Cutting: shearing can be easily achieved with sufficiently powerful machines
and freshly sharpened blades. When cross-cutting is necessary, intermediate local grinding
is required on edges (already work-hardened).
Machining
By standard methods allowing for work-hardening : the edges of the tool should bite beyond the work-hardened zones, necessitating a rigid machine.
·
Drilling: using supercarburized cobalt alloy high speed steel
bits of HSSCO type (AFNOR
grade 2-9-1-8, AISI grade M42), with reinforced shape, 130° point angle, long twist, low
cutting speed (2 – 3m/min.),
high feed, lubrication using soluble oils.
The
depth of the hole to be drilled should not exceed 3 times the bit
diameter.
(Other
solutions: 3 nibbed bits with carbide reinforcement, concrete drill bits, hot
drilling).
·
Milling: using supercarburized high speed steel tools of HSSCO
type (AISI grade M42) or carbide tipped tools (ISO grade K10) and high feed (as
for drilling) to bite beyond work
hardened
zones.
Punching
is possible on sufficiently powerful equipment and with tools in good condition
(avoid
denting shocks).
Forming
Bending and rolling are
easy: to be performed cold only (at workshop temperature). Avoid forming directly on zones previously
work-hardened (e.g. sheared edges), carry out grinding of these areas.
Welding
Using standard procedures taking into account : high coefficient of expansion, low thermal
conductivity, risk of carbide precipitation above 300°C (572°F).
Weld Metal:
·
Heterogeneous welds (most common practice):
For
manual arc welding typical deposits recommended are 18Cr8Ni6Mn or 20Cr10Ni3Mo
(class
A5.4E307 or 5.4E308Mo per AWS).
For
semi-automatic welding under gas the same type of deposit is used in
-
solid wire – class A5.2ER 307 or A5.9ER 308 Mo per AWS
- coated wire –
class A5.22E 307T or A5.22E 308 Mo T per AWS
·
Homogeneous welds (work-hardenable deposit)
Typical
deposit 12Mn3NiMo (class A5.13E FeMn per AWS) for manual welding.
For
semi-automatic welding coated wire of similar composition, with or without
protective gas.
General Recommendations:
Welding is performed with low heat-input E,20KJ/cm, interpass temperature limited to ≅ 100°C
(212°F) with water-cooling, if necessary between each pass. Any distortion can be hammered out.
N.B. NEVER PREHEAT.
Full specification and details are available on request.
The above information is provided for guidance purposes only.
For specific design requirements please contact our technical sales staff.
Unit 89 Marston Moor Business Park,
Rudgate,
Tockwith, York YO26 7QF
Tel: 01423
359111
Fax: 01423
359222