PLATEROWANIE WYBUCHOWE

1
VŠB-Technical University of Ostrava , Czech
Republic, department of Material
engineering. EPNM-2010MECHANICAL PROPERTIES OF
SANDWICH MATERIAL STEEL Cr18Ni10 Ti AFTER
EXPLOSIVE CLADDING
Dmytro OSTROUSHKO1), Lubomír CÍŽEK1) Zygmund
SZULC2) , Robert BANSKI2) , Rafal MOLAK 2) 1)
VŠB-TU Ostrava-CR, 2) Explomet Opole-Pl ., 2)
Politechnika Warszawska-Pl
2
Introduction

• Metal surface protection has a significant role
  for materials applied in corrosion medium.
  Usually material used in the case of heavy
  products are very expensive. That is why a thing
  layer from this material is applied on the
  surface of basic material.
• One of methods used for creating such sandwich
  materials is explosive welding application.

3
Background

• Method of explosive welding became recently
  very popular and is frequently used, as it brings
  about many advantage.
• Use of this method considerably reduces
  material costs and makes it possible to join
  materials, which cannot be otherwise joined
  together (e.g. Ti steel, Cu alloys steel and
  others).

4
Objective
Aim of my work is to identify the
characteristics and behavior of materials
TiCr18Ni10 steel after Explosive Cladding used
in heat exchanger in the chemical equipment.
5
Methodology preparation of materials for
joining
Saving explosives for the top sheet
followed eplosion
Saving sheet metal base
6
Samples for the fatigue test
The samples without heat treatment , (was marked
- VS) and the samples after heat treatment -
annealing at temperatures of 600 C (was marked
- TZ). Time held at the isothermal temperature
was 1.5 h with subsequent cooling in air.
The samples were taken by mechanical cutting in
order to prevent change of micro-structure of the
material.
The samples dimension was 12 x 10 x 100 mm

7
Fatigue tests were performed on the fatigue
testing machine MTS (material test sistem) type
810 at the Technical University Politechnika
Warszawska. Testing rods were subjected to load
by a three-point bending.

• schematically shown in this figures

Length of the tested part of the fatigue test rod
L was identical in all the samples namely 80 mm
8
Structures samples in etching state
Micrograph of the stainless steel
The grain size 45.3 ?m without the HT
The grain size 35.2 ?m with the HT
Micrograph of the titanium matrix
The grain size 18.6 ?m without the HT
The grain size 19.2 ?m with the HT
9
VICKERS microhardness
The blue line samples without HT The red line
samples with HT
10
Results of fatigue test
The amount of the force (kN) Number of cycles to fracture (N)
10 5 904
8 22 159
5 249 744
4,8 275 856
4 790 827
The amount of the force (kN) Number of cycles to fracture (N)
10 Plastic bending
8 12 606
5 272 143
4,8 350 412
4 2 000 000 (without breaking)
Ti steel(CrNi)after HT
Ti steel(CrNi) without HT
11
Wöhler curve
Wöhler curve of samples without HT
Wöhler curve of samples with HT
12
Samples after fatigue test
samples without HT after fatigue test
samples with HT after fatigue test
In the samples without HT the crack at lower
stresses propagates right to the basic material,
and at bigger loads the crack propagates only to
the weld, and then continues to propagate along
the welded joint . Situation in the sample with
HT at higher stresses is the same as in the
sample without HT. In lower stresses the crack
does not propagate into the basic material as
distinctly as in the sample without HT.
13
Conclusion
In collaboration with the company EXPLOMET the
following materials were joined Ti steel
CrNi(18/10), including control of quality of the
joined plates. The determination of
micro-hardness are revealed that in the zone of
the joint a deformation of materials occurs. As
we foundout the sample with heat treatment have
higher service lifetime as the sample without
heat treatment,which are very positive for this
component employed in chemical equipment. More
detail observations of these particles will be
focused in future works.
14
Thank you very much for your attentionAcknowled
gementThe authors are grateful to the Ministry
of Education of Czech Republic for financial
support of the project MSM 6198910015. Czech
Republic Poland co-operation was realized with
aim of project Interreg IIIa.