焊接方案012

工程焊接 Project weld

一 概况 General

上海SECCO90万吨／年乙烯工程26万吨／年丙烯腈装置，工艺管道11800延长米，折合243867吋／口，需现场制作的（除焚烧炉外）储罐11台，最大7000米最小300米。涉及焊接的材质现已知有10种。（除焚烧炉）分别是：Q235A、Q235B、15CrMo、CS、20、316L、316、304L、304、304SS。不锈钢焊接占的比例较大，焊接工作量主要集中在工程的中后期，加强管理，提高管道预制比例，严格工艺纪律，实现SECCO提出的一次焊接合格率96％，正点、高质量地建好丙烯腈装置。

Shanghai SECCO 900,000T∕A ethane Project and 260,000T∕A AN installation, process piping 11,800 extend meter, reduced 243,867 DB, request storage tank 11 stations which are manufactured in site (except for burning installation), the biggest storage tank is 7000 cubic meter, the smallest is 300 cubic meter. Materials which have been know refer to weld the biggest have 10 types. (except for burning installation) They are: Q235A, Q235B, 15CrMo, CS20, 316L, 316, 304L, 304, 304SS. SS weld?s

proportion is rather big, weld amount of work mainly focus on the middle-back date of project, reinforce management, enhance the proportion of piping prefabrication, strictly strengthen process discipline, realize once weld percent of pass 96% which is by SECCO, complete AN installation well and high quanlity.

二 编制依据 Orgernization base.

1 中国石化兰州设计院资料。 SLDI material 2 施工图纸。

Construction drawing.

3 上海SECCO有关技术文件。

Related technical document of Shanghai SECCO. 4 中国石化第五建设公司有关资料文件。

Related material document of the fifth construction company of SINOPEC 5 国家及行业标准规范。

Standard and specification of country and craft.

6 《锅炉压力容器压力管道焊工考试与管理规则》国质检总局.

“ Weld examination and management rules of boiler, pressure ressels and pressure pipling “quality inspection department of China.

7 《钢制压力容器焊接工艺评定》JB4708－2000

Weld process assessment of steel pressure ressels JB4708-2000. 8 《石油化工工程焊接工艺评定》SHJ509－88（可能有新版）

weld process assessment of petrochemical project SHJ509-88 (may have new version)

9 《钢制压力容器焊接规程》JB／T4709－2000

Weld rule of steel pressure vessels JB /T4709-2000. 10

1)《石油化工立式圆筒形钢制储罐施工工艺标准》SH／T3530－2001

Process standard of construction of petrochemical vertical cylinder shape steel storage tanks SH/T3530-2001

2)《现场设备、工业管道焊接工程施工及验收规范》GB50236-98

Weld project construction and acceptance criterion of equipments in site and industry piping GB50236-98.

3)《工艺金属管道工程施工及验收规范》GB50235-97

Process metal piping project construction and acceptance cirterionGB50235-97

4)《钢结构工程施工及验收规范》GB50205-2002

Steel struction project construction and acceptance criterion GB50205-2002

5)《石油化工剧毒、易燃介质管道工程及验收规范》SH3501-2001

Petrochemical strong poison and inflammable medium piping project and acceptance criterion SH3501-2001

6)《石油化工异种钢焊接规程》SH3526-92 Weld rule of petrochemical different steel SH3526-92

7)《石油化工工程铬钼耐热钢管待焊接技术规程》

Waiting weld technical rule of petrochemical project chrome molybden head-resistant steel pipe SH520-91

8)《石化化工工程高温管道焊接规程》SH3523-92

Weld rule of petrochemical project high temperature piping SH3523-92

9)《焊接用钢丝》GB1300-77 Steel wire used in weld GB1300-77

10)《碳钢焊条》GB5117-85 CS welding rod GB5117-85

11)《不锈钢焊条》GB983-85 SS welding rod GB983-85

12)《低合金钢焊条》GB5118-85 Low alloy steel welding rod GB5118-85

13)《焊条质量管理规程》JB3323-83

Quality management rule of welding rod JB3323-83

14)《焊缝符号表示法》GB324-88

Welding seam sign expression method GB324-88

三 工程中钢材及其焊接

Steel material and weld in project. 1 低碳钢的焊接 Law CS. weld

丙烯腈装置中CS、20、Q235A、Q235B属低碳钢系列。应含碳量较少（≤0.25％），其它合金元素添加很少，因而焊接性良好，焊前一般不需预热。塑性较好，焊接接头产生裂纹的倾向小，适应各种位置施焊。工程中低碳钢材料主要用于钢结构、给排水、一般介质的管道及容器。材料厚度δ4～22，最大管径D1820mm。20＃管子，

δ19、δ22两种壁厚是否需要预热和热处理按设计要求。

Such as :CS, 20, Q235A Q235B they belong to low CS series in AN installation. Among of them , amount of carbon is low (≤0.25%) and other alloy factors are very little too, so their welding performance is better and pre-heat is not necessary before weld .Plasticity is better is better, crack tendency from welding joint is little, they adopt weld in every position. In construction, low CS material is mainly used in steel structure, feed-drain water, normal medium piping and vessel. Material thickness is from δ4 to 22, biggest piping diameter is D1820mm. δ19 andδ22 from class 20 pipe, is their wall-thickness perform to preheat and heat-treatment is performed according to the design requirement.

四种材料的具体焊接规范见表1。

Detailed weld criterion of four materials include in following table one. 2 15CrMo钢的焊接

Weld of 15CrMo steel.

15CrMo钢属珠光体耐热钢,是一铬钼为主要原料的低合金钢（珠光体＋铁素体）。它的高温强度和高温抗氧化性较好，装置中主要用于供热系统。焊接铬钼耐热钢时，焊材选用要保证焊缝金属的化学成分，最大限度地接近被焊钢材的化学成分。

15CrMo steel belong to perlite heat-resistant steel and is low alloy steel and its main material is chrome and molybder (perlite ferrite).Its strength and antioxidation properties in high temperature are better, it is used in feed heat system in installation. When weld chrome molybder heat-resistant steel. Weld material must assure chemical elements of welding seam metal and maximun close to the chemical elements of being welded steel material. 1）、坡口加工及检查

Working and inspection of groove.

管子切割及坡口加工宜采用机械方法，当采用氧－乙炔火焰切割时，应清除熔渣、氧化皮，并将表面凹凸不平处打磨平整。坡口加工后应进行外观检查，坡口表面不得有裂纹、分层等缺陷。若设计要求对坡口表面进行无损探伤时，应执行JB4730标准，探伤范围为坡口及其两侧各20mm处。

Pip cutting and groove working shall adopt mechanical method. When adopt oxygen-ethyne flame cutting, clean out slag, oxide skin and make the rugosity surface scour level. Perform to inspect appearance after working groove, surface of groove shall not have fault of crack and layer ect. If NDT for is required by design , should perform standard JB4730,the range of crack detection is in the place zoom of groove and it?s both sides. 2）、预热 Preheat

焊接接头易产生冷裂纹倾向和再热裂纹倾向，为了避免产生上述现象，焊接时一般都要求焊前预热。15CrMo焊前预热温度若设计无要求，δ≥10mm时，t>150℃。

Weld joint is easy to work crack and re-crack, in order to avoid the phenamenon, normally request to preheat before weld. If the preheat temperature to 15CrMohave not requirement in design, whenδ≥10mm时，t>150℃。 3）、焊后缓冷

Slow cooling after weld

焊后缓冷是焊接这类钢必须严格遵守的原则，即使在炎热的夏天也必须做到。一般是焊后立即用石棉布覆盖焊缝及近缝区。

Slow cooling is the rules complied with by weld steel , it is also done in hot

summer. The method is that immediately cover welding seam and close seam area with asbestos cloth after weld. 4）、装配焊接 Assemble weld

焊接时，需要量一次焊完，最好不要中断，如果需中间暂停时，也应使已焊部分缓慢冷却。再进行焊接前，必须仔细清理检查，并重新预热。不允许进行强制装配，装配定位焊时也需预热。

During the course of weld , do not interrupt and complete it once. If pause is requested, make the welded parts slow cooling. Before assemble, weld next time must clean and inspect carefully and preheat again. Do not permit forced, preheat is necessary while assembling locating weld. 5）、焊后热处理 Heat-treatment after weld

焊后热处理温度：650～700℃。 Heat-treatment temperature=650-700 恒温时间：每毫米壁厚恒温时间3分钟，且不少于30分钟。

Constant temperature time constant temperature time for wall-thickness per-millimeter.is not less than 30 minutes. 6）、热处理后硬度测定：（见表二）

Hardness measurement after heat-treatment:(see table two)

项目 内容 item content 管子外径大于57mm时，检查热处理焊口总数10%，管子外径检查焊口数小于或等于57mm时，检查热处理焊口总数的5%，且不少于量 5% inspect the piper outside cliameter is more than 57mm, inspect heat-treatment amount of crater total is 10%, or else, inspect heat-treatment crate total is crater 5%and less than 5% 每个焊口不少于一处每处三点。如图所示： 1 2 3 硬度测定 Harlness measurement 1、焊缝 2、热影响区 3、母材 Each crater is less than one position and each position have three point. Following chart= 1 welding seam 2 heat affection area 3 parent material 合格标准 焊缝硬度一般不超过母材布氏硬度HB＋100； passing hardness of welding seam do not exceed parent material standard Brinellhardness HB+100 不合格处理 defective treatment

硬度值超过规定，加倍检查，仍不合格重新热处理，并做硬度测定. If the hardness value exceed regulations, doubling inspect, If result of inspection do not pass, perform heat-treatment again and do hardness measurement. 15CrMo钢的具体焊接规范见表一。

Detailed weld specification for 15CrMo steel see table one. 3 奥氏体不锈钢的焊接

Weld of austenite stainless steel..

丙烯腈装置不锈钢材料较多，有316L、316、304L、304、304SS五种。主要用于有毒、腐蚀、管道和容器，所以质量要求较高。

Stainless steel material in AN installation have five types such as:316L, 316, 304L, 304, 304SS. They are used in poison, erosion, piping and vessel; so the requirement in quanlity is more high. 1）、奥氏体不锈钢的焊接特性

Weld performance of austenite stainless steel.

焊缝在450～850℃温度区间停留过长，一般认为650℃为晶间腐蚀敏感温度，焊缝或热影响区只要在这个温度停留十几秒到几分钟，就会产生晶间腐蚀。奥氏体不锈钢也易产生热裂纹。

Wellaing seam is under the temperature 450-850℃ for a long time , normally temperature 650℃ is intercrystalline corrosion sensitive temperature, if welding seam or heat affection area delay form ten and several second to several minutes under the high temperature , work intercrystalline conosion .Austenite stainless steel also work heat crack. 2）、奥氏体不锈钢的焊接工艺要点

Key Points to Welding Procedure of Austenitic Stainless Steel

无论是SMAW、TIG，都必须首先从焊接材料选择上尽量消除或减弱上述缺陷的影响。主要是选用超低碳焊丝（焊条），选用中流加稳定化元素的，能使焊缝金属获得双相组织（奥氏体＋铁素体）的。

Regardless of SMAW and TIG, first the influence of above-mentioned defects must be eliminated or weakened as much as possible from selection of welding materials, i.e. mainly select extra low carbon welding wire (electrode), and the welding material which is of medium current and blended with the stabilized element and which can make weld metal get diphase structures (austenite and ferrite). 3）、焊接注意事项 Welding notes

采用小的线能量 Less heat input shall apply.

采取冷却措施，要采取强制冷却(水冷、吹压缩空气等)措施，控制层间和焊后温度，尽量减少在450～850℃的停留时间.

Take proper cooling measures, namely be to take the forced cooling (e.g. water cooling and blowing with compressed air) measures, control interpass and post weld

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