Innovative Stainless Steel Applications in transport ... - Euro Inox

More documents

Recommendations

Info

(a) (b) Figure 29. Salt-spray test arrangements used in the projects: (a) BUS project tube and sheet details and (b) DOLTRAC panel sample sections. Field test Field testing is the only type of test that provides information from actual service conditions. The disadvantages are that such tests are expensive and time-consuming and have to be performed at several locations, to take account of the effects of local environmental variations. In the BUS project, long-term field tests with durations of up to almost two years were performed in three locations, each with different climatic conditions, to ensure valid results (Table 11). Table 11. The details of the field corrosion tests (BUS). Location Climate type Vehicle type Test duration Total distance (months) (km) Helsinki urban with de-icing salt local bus 23 87,040 Rome urban inland local bus 18 42,011 Bay of Gibraltar marine local bus 21 59,320 Spain (Madrid) urban inland coach 19 105,395 These tests were performed using test racks mounted under buses or coaches in regular service. Mock-ups and different kinds of weld samples were also included in the tests, to obtain reliable long-term information about corrosion performance, for design and manufacturing purposes (Figure 30). More detailed information concerning the test procedures can be found in BUS (p. 222). 36
(a) (b) Figure 30. Photograph from the test racks and specimens used in the long-term field tests: (a) a readily assembled rack and (b) a rack installed underneath a bus (BUS). 2.4.4 Corrosion test results Ferritic stainless steels The atmospheric corrosion resistance of ferritic stainless steels is directly proportional to the chromium content of the alloy. Type EN 1.4003 is not recommended for outdoor architectural applications, due to its poor localised-corrosion resistance – which causes surface staining, even in rural conditions, unless protected with coatings. The same applies to its use in vehicle-chassis structures, as the results of the salt-spray and field tests showed (Figure 31, Figure 33 and Table 12). Welding further reduces the localised-corrosion resistance of EN 1.4003. Its corrosion resistance can be improved by post-weld surface treatments such as pickling, which, together with shot peening, gives the best results (Kyröläinen et al. 2000). Although EN 1.4003 is not recommended for outdoor architectural applications, due to its poor localised-corrosion resistance, it has successfully been used in open train wagons for bulk transport. This low-alloyed stainless steel showed lower life cycle costs than wagons made of painted steel, that required severe maintenance work every 8-10 years (Atlas Specialty Metals 2008). Recently, ferritic stainless steels with higher chromium content, with or without molybdenum, have been developed and adopted for vehicle applications. The corrosion resistance of EN 1.4521, with 18 % Cr and 2 % Mo, for example, is expected to be similar to that of EN 1.4401 austenitic stainless steel. Furthermore, ferritic stainless steels with 17 % Cr and 1.5 % Mo (e.g. 1.4113, 1.4526) are being used in automotive trims. Ferritic stainless steels should also be considered when there is a risk of chlorideinduced stress corrosion cracking, since they are virtually immune to it. 37
Page 1 and 2: Preface This publication is the mai
Page 3 and 4: Contents Preface ..................
Page 5: List of symbols Mechanical properti
Page 8 and 9: Figure 1. Rear view of El Capitan.
Page 10 and 11: In Japan and the Asia-Pacific areas
Page 12 and 13: 12 Figure 13. Delhi metro coach (Go
Page 14 and 15: 1.3 Bus and coach applications 14 A
Page 16 and 17: 1.4 Future potential Future prospec
Page 19 and 20: 2. Materials By definition, stainle
Page 21 and 22: use higher nitrogen contents in aus
Page 23 and 24: Grade 1.4318 stainless steel was su
Page 25 and 26: MPa). Table 7 shows the format and
Page 27 and 28: 1. Design using minimum specified v
Page 29 and 30: Table 9. The most common stainless
Page 31 and 32: Table 10. Physical properties of so
Page 33 and 34: for example, in the case of lap joi
Page 35: to develop new de-icing chemicals,
Page 39 and 40: Austenitic CrNi and CrNiMo stainles
Page 41 and 42: Figure 33 shows the behaviour of fe
Page 43 and 44: (a) (b) Figure 35. Localised corros
Page 45 and 46: visual and not detrimental to struc
Page 47 and 48: Reduction factor 1 0.9 0.8 0.7 0.6
Page 49 and 50: It is typical of cold-worked stainl
Page 51 and 52: Thermomechanical treatments can be
Page 53 and 54: Table 17. The minimum values for co
Page 55 and 56: 3. Lightweight structures and desig
Page 57 and 58: K joints The requirements for K joi
Page 59 and 60: Figure 42. Overlapping joint (Yrjö
Page 61 and 62: Another typical way to join a hollo
Page 63 and 64: There are some disadvantages with a
Page 65 and 66: New challenges have to be met in bo
Page 67 and 68: Stiffness parameters Despite the li
Page 69 and 70: Figure 52. An experimental, sandwic
Page 71: 71 Figure 53. Stainless steel sandw
Page 74 and 75: values are shown in Table 20. A com
Page 76 and 77: Springback was determined by measur
Page 78 and 79: A “three-roll” (pyramid-type) b
Page 80 and 81: angle of 180 °. Figure 58 shows th
Page 82 and 83: design and the manufacture of the t
Page 84 and 85: Combined with modern pulsing techni
Page 86 and 87:
possibility of transferring the bea
Page 89 and 90:
5. Properties of lightweight struct
Page 91 and 92:
Table 28. Fusion welding results fo
Page 93 and 94:
welding mechanical treatments. Howe
Page 95 and 96:
performance of a weld-joint detail
Page 97 and 98:
2400 N. Thus, the specified fatigue
Page 99 and 100:
limited number of static bending te
Page 101 and 102:
material strengths or manufacturing
Page 103 and 104:
section at a velocity of 3.0 m/s. F
Page 105 and 106:
(a) (b) (c) Figure 65. (a) Deflecti
Page 107 and 108:
Figure 67. Panel sections after lon
Page 109 and 110:
6. Life cycle issues The transporti
Page 111 and 112:
and services, occurring throughout
Page 113 and 114:
100 % 80 % 60 % 40 % 20 % 0 % Mater
Page 115 and 116:
(especially in the case of lower-al
Page 117 and 118:
Acknowledgements The following orga
Page 119 and 120:
References Ala-Outinen, T. 1996. Fi
Page 121 and 122:
DIN 6935. 1975. Kaltbiegen von Flac
Page 123 and 124:
Federation of metals industries. ME
Page 125:
UNEP 2002. Industry as a partner fo
show all

Innovative Stainless Steel Applications in transport ... - Euro Inox

Create successful ePaper yourself

Delete template?

Save as template?