870
D. Matsuura et al.
A-1
A-1
A-2
A-2
A-3
A-3
Photograph 4 Appearance after two years
The test was conducted for two years. Photograph 3 shows the starting test pieces
and Photograph 4 shows after two years.
Material
A-1: Initial state is a machined surface. The surface has become white due to the
overall erosion, and scratches of grinding have become thinner.
A-2: Initial state is a machined surface. The metallic luster is slightly lost, and
scratches of grinding remain.
A-3: The surface is clearly eroded, and both specimens were deeply damaged.
Under this environment, erosion resistance is insufficient.
Welded parts
A-1: The erosion is clearly observed on the welded part. The weld is more eroded
than the specimen itself.
A-2: Slight erosion is observed. The erosion is minimum among test.
A-3: Severe erosion is observed.
Crevice Corrosion Test
A test was preparing in the gaseous zone and liquid zone. The test device is attached
to the actual equipment shown in Photograph 5.
The test was conducted for eight months. There was no change in the weight and
thickness of the sample pieces. Corrosion rate is calculated to less than 0.1 mm/year.
The results imply that A-2 shows excellent corrosion resistance and abrasion
resistance in this condition. Therefore, A-2 was decided to adopt in new equipment.
D. Matsuura et al.
A-1
A-1
A-2
A-2
A-3
A-3
Photograph 4 Appearance after two years
The test was conducted for two years. Photograph 3 shows the starting test pieces
and Photograph 4 shows after two years.
Material
A-1: Initial state is a machined surface. The surface has become white due to the
overall erosion, and scratches of grinding have become thinner.
A-2: Initial state is a machined surface. The metallic luster is slightly lost, and
scratches of grinding remain.
A-3: The surface is clearly eroded, and both specimens were deeply damaged.
Under this environment, erosion resistance is insufficient.
Welded parts
A-1: The erosion is clearly observed on the welded part. The weld is more eroded
than the specimen itself.
A-2: Slight erosion is observed. The erosion is minimum among test.
A-3: Severe erosion is observed.
Crevice Corrosion Test
A test was preparing in the gaseous zone and liquid zone. The test device is attached
to the actual equipment shown in Photograph 5.
The test was conducted for eight months. There was no change in the weight and
thickness of the sample pieces. Corrosion rate is calculated to less than 0.1 mm/year.
The results imply that A-2 shows excellent corrosion resistance and abrasion
resistance in this condition. Therefore, A-2 was decided to adopt in new equipment.