WYJ079                              15MnNi

1. applicable scope:

The technology conditions apply to nuclear security second and third pressure vessels and equipment with 15 MnNi steel gate.

4. Technical requirements

4.2 delivery status

Steel normalized state delivery.

4.4 sample after welding heat treatment state simulation of mechanical properties and process performance should be consistent with the table 2 ~ table 4 regulation, sample for horizontal direction.

Table 2 The mechanical properties of the steel plate and process performance

Table 3 The steel plate V impact toughness requirements

note：（1）Three sample of impactonly allows a sample tensile results less than average；

（2）When the width of 7.5 mm or 5 mm of small sample, impact energy should be not less than the average respectively in the table of the rating of 75% or 50%。

Table 4    200℃High temperature and performance requirements

4.5Grain degree requirements

The steel plate grain degrees according to  GB/T6394-2002 method to assess, grain degree level 6 or more fine requirements。

4.6Non-metallic inclusions requirements

The steel plate non-metal inclusions according to GB/T10561-1989 evaluation method, the content should be consistent with the specified below：

Academic（Thick or thin）≤1.0级；B（Thick or thin）+Category

（Thick or thin）≤3.5级；D（Thick or thin）≤1.0级。

4.7Sample simulation after welding heat treatment system

Charging temperature：≤400℃；

Rate of temperature：55～80℃/h；

holding temperature：580～620℃

soaking：6小时；

cooling rate：temperature >400    55～100℃/h，≤400℃air cooled。

4.8The surface quality of the steel plate in trimming should be done after side check, are not allowed to have opened or horizontal stratified phenomenon。

4.9ultrasonic examination

Delivery status steel should be according to the provisions of ASTM A578 detection, grade C qualified