1.Product Overview

With new coal-fired power plants no longer feasible, extending the life of aging plants has become a major challenge. This has increased demand for evaluating the remaining creep life of main steam pipes and other components. In response, the small punch creep (SPC) testing method was developed to extract and test thin specimens with minimal damage. However, since SPC is an equi-biaxial test, it cannot directly utilize the vast database of uniaxial test data. To address this, demand has grown for a uniaxial creep testing machine that accommodates thin specimens similar to those used in SPC. This newly developed machine enabled uniaxial creep testing using specimens nearly identical in size to SPC specimens (5 mm wide, 10 mm long, and 0.5 mm thick).

2.Product Description

The Ultra Miniature Creep (UMC) testing machine is a lever-type system that applies load using dead weights. Tests are conducted in an argon gas environment, with the specimen section enclosed in a chamber. Due to the specimen’s tapered shoulders, it is automatically aligned when chucked. An electric furnace surrounding the chamber provides heating.
The specifications of the machine are as follows:

・Maximum test load: 1 kN
・Maximum test temperature: 1,000℃ (argon gas environment)
・Overall dimensions: W600 mm × H900 mm × D330 mm
・Displacement measurement: DTF displacement gage (2 units)
・Load application : Lever type (5:1)
・Specimen size : Outer dimensions: 10 mm × 5 mm; Reduced-section length: 5 mm; Reduced-section width: 0.5 to 2 mm

The specimen’s tapered shoulders enabled automatic alignment by simply setting it into the fixture. Although the miniaturized specimen raises concerns about oxidation effects on creep strength, this machine minimizes them by enclosing the specimen in an inert gas (argon) chamber. The chamber’s open-top design eliminates metal seals like bellows, significantly reducing sliding resistance for high loading accuracy. The compact chamber and furnace, with low heat capacity, allow high-temperature testing with minimal power consumption, sufficiently supplied by a standard household power outlet. The machine’s overall size fits within a standard office desk, allowing operation with very-low running costs.  

Fig.1 Ultra-Miniature creep testing machine.

Fig.2 Test specimen shape.

Fig.3 Chamber structure.

3.Sales Performance

This machine is our in-house development and holds a 100% share of the market. Four units of this testing machine have been sold domestically, and 20 units installed in our facility are currently in operation for contract testing. Due to frequent requests from research institutions, the machines are in continuous use. We have also received many inquiries about the machine, and the number of units sold is expected to increase.

Kobe Material Testing Laboratory Co., Ltd

47-13 Niijima, Harima-cho, Kako-gun, Hyogo 675-0155