Research On The On-line Small Punch Tests Device And Its Experimental Investigation

Small Punch Test (SPT) is a new kind of testing technology, which is put forward and developed in the early of1980s. This technology has a widely application prospects in on-line sampling testing for equipments.The first step of applying this technology is sampling from on-line equipments, therefore, two kinds of sampling devices has been developed. However, these devices still cannot meet the demand of SPT sampling. Consequently, developing a new kind of device will promotes the development of SPT.This article makes analysis about these devices, and points out that the limitations and defects of cutting tools they used. The electroplated diamond wire is a kind of advanced cutting tool which is manufactured by solidifying the diamond particles on the metal wire substrate, and has a lot of advantages comparing with the traditional cutting tools. Aiming at the advantages of electroplated diamond wire, this article put forward new method of developing sampling device which is based on the electroplated diamond wire, in order to meet the on-line sampling demand of high temperature vessel and steel pipes in some industries, such as power and petrochemical.After accomplished project demonstration, mechanical design and calculation, and machining, this article developed a new kind of SPT sampling device which use electroplated diamond wire as cutting tool. The experiment shows that it has a high reliability. In the process of sampling, the volume is smaller and the calorific value is lower. Because of this, it has low damage to equipment and no heat affected zone basically.This device conquers the defects of SPT sampling devices have been developed now, and can meet sampling demand of steel pipes within a certain range in diameter, which will have an positive effect on the development of SPT.Using duplex stainless steel, this article made study of the influence of different loading rates to SPT results. The research results show that different loading rates have a little influence on some parameters of SPT results, but the influence is liner and not much. The relationship of other parameters and SPT results has no rules to follow, and needs further research.