09MnNiDR Pressure Vessel Steel Plate

GB 3531 09MnNiDR is Manganese-Nickel alloy steel, centigrade the letter D is for low temperature using, the letter R is for boiler and pressure vessel using.The low temperature impacting test shall be done for 09MnNiDR centigrade, the impacting energy value should above 34 J. 

09 indicates that the content of C is about 0,09%, Mn indicates that the content of Mn is about 1%, and Ni indicates that there is a trace of alloying elements, generally higher than 0, 30 are alloying elements. It needs to be expressed. D means "low temperature" is the first letter of pinyin. R stands for "container" and is the first letter of pinyin.

09MnNiDR steel is ferrite + a small amount of pearlite low temperature steel. Due to its low carbon content, it belongs to low-alloy structural steels and Mn and Ni are its main alloys. Mn mainly enhances the strength of steel by solid solution strengthening, while Ni can improve the low temperature toughness of ferrite and has the effect of significantly reducing the temperature of cold and crisp transitions. 

Its carbon equivalent is less than or equal to 0.44, hardenability tends to be small, and cold cracks are not easily formed. The weld has good plasticity and toughness, and usually does not require preheating. When the plate thickness exceeds a certain thickness, the rigidity of the joint is restricted, or the carbon equivalent is high, preheating should be considered. However, the preheating temperature should not be too high, otherwise the grains in the HAZ will grow up and oxides will precipitate at the grain boundary. Therefore, the welding line energy and interlayer temperature should be controlled during welding, and stress-relief heat treatment should be performed after welding.

Mechanical Property and Application:

1. Steel is a special plate for pressure vessels with a yield strength grade. It has good comprehensive mechanical properties and processing properties. The content of phosphorus and sulfur is slightly lower than that of ordinary steel. In addition to higher tensile strength and elongation requirements than ordinary steel, it is also necessary to ensure impact toughness. It is currently the most widely used steel plate in pressure vessels in my country.
2. The steel is ferrite + a small amount of pearlite type low temperature steel. Due to its low carbon content, it is a low-alloy structural steel with Mn and Ni as the main alloy. 09mnnidr is what 09 means.
3. Mn mainly improves the strength of steel through solid solution strengthening, while Ni can improve the low-temperature 09MnNiDR toughness of ferrite, and has the effect of significantly reducing the cold brittle transition temperature. Its carbon equivalent is less than or equal to 0, 44, has a small hardening tendency, and is not easy to form cold cracks. The weld has good plasticity and toughness, and usually does not require preheating. When the thickness of the plate exceeds a certain thickness, the rigidity of the joint is relatively large or the carbon equivalent is high, preheating should be considered. However, the preheating temperature should not be too high, otherwise the grains in the heat-affected zone will grow and oxides will precipitate at the grain boundaries. Therefore, the welding heat input and interlayer temperature should be controlled during welding, and stress relief heat treatment should be carried out after welding.

Technical Requirements & Additional Services:

• Charpy V-notch impact test at low temperature
• Cutting and welding as per end user’s demands
• Simulated post-welded heat treatment (PWHT)
• Rolling under standard NACE MR-0175 (HIC+SSCC)
• Issued Orginal Mill test certificate under EN 10204 FORMAT 3.1/3.2
• Ultrasonic test under GB/T2970,JB4730,EN 10160,ASTM A435,A577,A578

Chemical Compostion(Wt.%):

Mechanical Properties:

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