【国外标准】 Standard Specification for Ductile Iron Castings for Paper Mill Dryer Rolls

This specification covers ductile iron castings for use in pressure containing paper mill dryer rolls. The castings shall be stress relieved through heat treatment and shall undergo chemical analysis and conform to the required chemical composition in total carbon, silicon, phosphorus, and sulfur. Tension test specimens shall be obtained from test coupons poured from the same iron as the castings represented and shall conform to the prescribed mechanical properties such as yield strength, tensile strength, and elongation. Hardness test shall be conducted on the material and shall meet the required Brinell hardness value.1.1 This specification covers ductile iron castings for use in pressure-containing paper mill dryer rolls at temperatures up to 450 °F [230 °C].1.2 No precise quantitative relationship can be stated between the properties of the iron in various locations of the same casting or between the properties of a casting and those of a test specimen cast from the same iron (see Appendix X1).1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard.1.3.1 Exception—Within the text, the SI units are shown in brackets.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.