Heat Treatment and PWHT Procedures 热处理及焊后热处理程序TABLE OF CONTENTS目录1.0SCOPE范围 (1)2.0REFERENCES参考文件 (1)3.0EQUIPMENT设备 (1)4.0HEATING METHODS加热方法 (1)5.0HEATING AND COOLING RATES加热和冷却速率 (1)6.0HOLDING TEMPERATURES AND ALLOWABLE RANGES保温温度和容许范围 (2)7.0INTERRUPTED POSTWELD HEAT TREATMENTS不规则的焊后热处理 (2)8.0TEMPERATURE CONTROL AND RECORDING温度控制和记录 (3)9.0RECORDING POSTWELD HEAT TREATMENT CYCLE焊后热处理记录周期 (4)10.0HARDNESS TESTED REQUIRMENTS AFTER PWHT热处理后的硬度测试要求 (5)11.0PRETECT DEFORMATION DURING HEAT TREATMENT热处理期间的防变形 (5)12.0RECORDS记录 (5)Attachment and Appendix List附件附录清单ATTACHMENT1:PWHT REPORT附件1：焊后热处理报告 (5)1.0S C O P E范围1.1This procedure specifies detailed requirements for performing post weld heat treatment(PWHT)该程序规定了进行焊后热处理的详细要求。
1.2This procedure was written to meet the requirements of ASME B31.3for heat treat temperatures,holding times,heating andcooling rates,and permissible heat treating methods when PWHT is required.该程序是根据ASME B31.3中针对焊后热处理的处理温度、保温时间、加热和冷却速率以及允许的加热方法来拟写的。
2.0R E F E R E N C E S参考文件Doc.No.Document TitleASME B31.3-2012Process Piping工艺管道3.0E Q U I P M E N T设备3.1Certification of equipment shall be provided upon request.应当根据需要提供设备的证书。
3.2Calibration certificate of temperature indicator shall be submitted and approved before use.使用温度指示器之前应当提交校准证书并获得批准。
3.3Recalibration reference paragraph9.2.参考段落9.2中关于重校的内容。
4.0H E A T I N G M E T H O D S加热方法4.1Gas heating method be utilized to perform PWHT利用燃气加热法来进行焊后热处理。
4.2Any other PWHT method requires prior approval of customer before use.使用任何其它焊后热处理方法之前都要客户的批准。
5.0H E A T I N G A N D C O O L I N G R A T E S加热和冷却速率5.1.The rate of the heating at the temperature above300Deg.C(572°F)shall not exceed220Deg.C(428°F)/Hr.for pipe wallthickness up to and including25mm(0.984in)/T maximum.For maximum pipe wall thickness more than25mm(0.984in)/T,the heating rate shall be(5588/T Where T=pipe wall thickness in mm).对于最大壁厚为25mm(0.984in)的管道，300℃(572°F)之后的加热速度不应超过220℃(428°F)/小时。
对于最大壁厚超过25mm(0.984in)的管道，加热速度为5588/T(T=管道壁厚mm数)。
5.2The rate of Cooling from the Soak temperature to a temperature above300Deg.C(572°F)shall not exceed275Deg.C(527°F)/Hr.For pipe wall thickness up to and including25mm(0.984in)/T in maximum.For maximum pipe wall thickness over than25mm(0.984in)/T,the Cooling shall be(6985/T Where T=pipe wall thickness in mm).对于最大壁厚为25mm(0.984in)的管道，从均热温度冷却到300℃(572°F)以上的速度不应超过275℃(527°F)/小时，对于最大壁厚超过25mm(0.984in)的管道，冷却速度为6985/T（T=管道壁厚mm数）。
6.0HOLDING TEMPERATURES AND ALLOWABLE RANGES保温温度和容许范围6.1Post weld heat treatment holding temperatures and times are specified on the Form-1and/or the Welding Procedure Specification(WPS).Additional limitations are imposed on the holding temperature range as stated below.表-1和/或德焊接工艺规程中规定了焊后热处理的保温温度和时间。
对于保温温度范围的额外限制如下所述。
6.2The holding temperatures are limited by Code requirements.When the pipe thickness≤20mm，don’t need to heat treatmentor we perform heat treatment according our customer requirement；规范要求限制了保温温度，当管壁厚小于等于20mm时，不需要退火，或者按照客户要求进行热处理。
6.3For dissimilar P-numbers,refer to the Form-1,WPS and/or the applicable code.In general,the heat treatment requirements for thehigher P-Number material should be used.如果部件编号不同，参考表-1、焊接工艺规程和/或适用的规范。
一般来说，应当采用较高级编号的材料的热处理要求。
7.0INTERRUPTED POSTWELD HEAT TREATMENTS不规则的焊后热处理7.1Interrupted postweld heat treatment is defined as decreasing below the minimum specified holding temperature or exceeding themaximum specified cooling rate and may be caused by loss of power,equipment malfunction,or operator error.不规则的焊后热处理被定义为降低至最小指定保温温度以下或超过最大指定冷却速率，可能是电源中断、设备故障或操作失误导致的。
7.2For welds in which the postweld heat treatment temperature has dropped below the minimum holding temperature withoutexceeding the specified cooling rate,actions should be initiated to restart the heat treatment as soon as possible.焊道焊后热处理温度降至最低保温温度以下，没有超过指定的冷却速率时，应当采取行动尽快重新开始热处理活动。
7.2.1The weldment shall be reheated at a rate not to exceed that specified by the applicable Code,and the holding temperature shallbe reestablished.The additional required holding time shall be calculated by finding time remaining to complete the postweld heat treatment from the first holding period.The weld shall be held at temperature for this time period or for one-half hour,whichever is greater.应当以不超过适用规范指定的速率重新加热焊件，并且恢复保温温度。
应当从第一保温阶段查明完成焊后热处理剩余的时间，来计算需要的额外保温时间。
应当对焊道保温此时间周期或者保温半个小时，两者取其大。
7.3For welds in which the maximum Code cooling rate was exceeded,the postweld heat treatment shall be redone for both the entireholding period and cool-down rate.If an interrupted heat treatment occurs,actions should be initiated to restart the heat treatment as soon as possible.如果超过了规定的最大冷却速率，应当针对整个保温阶段和冷却速率重新进行焊后热处理。