JIS G 4312-1991 Heat-Resistant Steel Sheets
JIS G 4312-1991, also known as Heat-Resistant Steel Sheets, is a standard established in Japan for the manufacture and testing of steel sheets used for high temperature applications. The standard prescribes the quality, properties and testing requirements for hot rolled and cold rolled steel sheets used for electrical components, such as transformers and motors, and other industrial equipment.
Steel sheets as specified in JIS G 4312-1991 must meet a certain set of requirements, standards and criteria. First, the steel sheet should be chemical composition tested and its chemical composition should be certified. In addition, the sheets should have good formability, weldability and corrosion resistance. The sheet must also have the required strength and toughness. The range of Surface Roughness should be below 1.6 microns and zero point Rz less than or equal to 2.5% of the sheet Thickness. In addition, the hardness of the sheet must be tested prior to delivery.
The strength of the steel sheet can be evaluated by conducting tensile and impact tests. The tensile tests should include tension tests and bend tests. Impact tests should include Vickers Hardness Test and Charpy Impact Test, which should measure the impact characteristics of the sheet. The Charpy Impact Test should also be carried out for temperature range from 20 to 400°C, in order to evaluate the impact strength of the sheet at various temperatures.
The JIS G 4312-1991 also requires that the steel sheets should be free from defects, are resistant to scale formation due to heat and should be properly oiled to protect against rust. The sheet should be properly rolled, the interface between each sheet should not be distorted or fatigued. Testing of the sheets should also include leakage current and thickness measurements.
JIS G 4312-1991 Standards are widely adopted throughout the industry and are used to insure that the heat-resistant steel sheets meet minimum safety and performance requirements as specified in the standard. Major industrial and electrical equipment manufacturers have accredited and approved the standard for use in their designs and operations. Manufacturers of steel sheets for high-temperature applications can get their products certified to the JIS G 4312-1991 specification, which is widely accepted in the industry.
