Portable indentation residual stress tester

Portable indentation residual stress tester

Product Introduction

Metal materials are an important material foundation for industrial production, and their properties directly affect the safe operation of equipment and facilities in fields such as natural gas, petroleum and petrochemicals, aerospace, power metallurgy, wind power, thermal power, nuclear power, and railway ships. As the service life increases, the mechanical properties of equipment materials inevitably deteriorate, posing a serious threat to the safety of equipment operation. Therefore, it is of great significance to evaluate the mechanical properties of materials. Traditional evaluation methods such as tensile testing, fatigue testing, fracture toughness testing, etc. can cause damage to the equipment when making samples, requiring shutdown for testing. Moreover, the testing time is long, the efficiency is low, and on-site testing cannot be conducted, so it is often unacceptable. In this situation, the indentation method for in-situ detection of minor damage in service equipment has emerged. The indentation detection method has been continuously developed and extended since hardness testing, and can now measure multiple mechanical performance parameters such as material tensile properties, residual stress, and fracture toughness.

Figure 1-1 Indentation Test Function

After years of technical research and development, the team has developed a "portable universal indentation tester" that calculates mechanical properties and residual stresses by recording the displacement load information generated by the intrusion of a specific shaped indenter into the material. It abandons traditional destructive testing concepts and can conduct on-site non-destructive testing, effectively avoiding equipment shutdown and damage detection. At present, the equipment has passed the accuracy test of Shengli Oilfield Testing Center, and compared with traditional blind testing methods, the error is less than 10%, which meets the requirements of engineering applications. The first domestic and international standard for measuring (welding) residual stress using indentation energy difference method, "Metal Material Residual Stress Testing indentation energy difference method", developed by the team, has been approved for CSTM standard approval.

Figure 1-2: Independently developed indentation testing technology

PMT-1000 is currently the latest equipment (PMT - XXX, PMT stands for Portable Mechanical Properties Tester, XXX is the maximum load capacity of the equipment, such as PMT-1000, with a maximum load capacity of 1000kg), mainly including a universal indentation tester, control system, and calculation software. It can achieve wired and wireless connection with computer terminals for equipment operation control, information transmission, and real-time calculation.

Figure 1-3 Universal indentation testing system

The indentation tester consists of four parts: the instrument body, a specific shaped indenter, a rotating and translating mechanism, and a magnetic fixed base, as shown in Figure 1-3. The instrument body is driven by a servo cylinder to control the ball or Nusselt indenter to press down and penetrate the tested material; The magnetic fixed base can quickly adhere to the surface of magnetic materials, ensuring the stability of the indentation testing process. At the same time, it can be controlled magnetically through a knob, making it convenient for the machine to adjust and accurately measure the points in the tested area.

Adopting two sets of control and data transmission systems, wireless and wired, suitable for various testing environments. The wired testing system adopts a LCD touch screen menu for parameter setting and press in control. The control box is compact and lightweight, easy to operate, and can be powered by batteries. It is not afraid of outdoor environments and data is stored in real-time on an SD card. The wireless testing system can be remotely controlled through a mobile app and computer software, with real-time data transmitted to the software, greatly reducing the size of the control box, making it more portable and convenient for measuring in special locations. The data is transmitted to the software for real-time processing and calculation, and the mechanical properties and residual stress results are directly generated with one click, achieving fast calculation of data and visualization of mechanical performance parameters.

The PMT-1000 universal indentation tester can measure both mechanical properties and stress, mainly used for safety assessment of energy equipment and non-destructive measurement of residual stress in on-site welding structures. It is widely used in industries such as material research, mechanical manufacturing, mining metallurgy, water conservancy engineering, railway transportation, chemical equipment, shipbuilding, aviation industry, and power construction. It is an important tool for non-destructive safety assessment and analysis in petrochemical, heavy equipment enterprises, research institutes, and production and construction.

execution standard

·ISO/TR 29381 Metallic materials - Measurement of mechanical properties by indentation test - Indentation tensile properties

·GB/T 21838 Instrumented indentation test for hardness and material parameters of metallic materials