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国标中TA2对应美标的Gr.2吗?

发布日期:2017-10-24 浏览次数:

A new grade for Titanium

一种新级别的钛

     Many ASTM International material specifications were written decadesago. While these specifications have evolved, the specified minimum propertieshave rarely been revisited since they were first established. In the interim,the industry has invested millions of dollars upgradingcapabilities to produce a6 better and more consistent product. In some cases, these advances may justify revising themechanical, chemical, or other requirements of corresponding ASTM specifications.

许多ASTM国际材料规范都是十多年前起草的。然而,尽管这些规范不断被修订,但自首次发布后,标准规定的性能指标下限却很少修订。在该规范运行期间,本行业已经投资数百万美元升级能力,制造出质量更稳定、性能更好的产品。在这种情况下,这些投资是ASTM标准的物理性能、化学成分或其他技术要求合理修订所必须进行的工作。

(在某些情况下,这些进步是可以证明ASTM 标准下物理性能,化学成分或者其他技术要求的修订是正确的。)

 Anexample of such an activity is the recent addition of the "H grades"to the ASTM titanium specifications by ASTM Committee BI0 on Reactive andRefractory Metals and Alloys.

举例来说,近期,ASTM BI0(活性和难熔金属及合金委员会)在ASTM纯钛规范中增加了一种"H "级别。                          

This paper discusses: Thebackground leading to this particular change, How thetraditional role of producers in property development was replaced by a usergroup that saw an economic advantage in the change, The importance ofthe ASTM committee consensus process, and A summary of the expected benefits.

本文讨论了:

1、引进这种"H "级别纯钛的背景

    2、注重经济利益的应用群体取代了制造商在提高产品性能方面发挥的重要作用

    3、在提高产品性能方面,传统生产商是如何被注重经济效益的用户群体所取代的?

    4、通过ASTM 委员会多数成员表决的重要性

    5、"H "级别纯钛的预期效益概述

 

BACKGROUND

The40 to 50-year-old data used to develop current ASTM titanium properties may nolonger represent modern material. Changes in production practice have resultedin more consistent material chemistry with reduced levels of residual elementswhose combined effect is not fully  understood. Producershave to control titanium ingot chemistry so accurately that their ability toachieve consistent results and variation in properties is vastly improved fromwhen the ASTM titanium specification property values were first established.

   背景

40-50年来积累的数据惯用于显示当前的ASTM纯钛性能的变化趋势,而不是有目的地为发展现有该牌号而收集。为使产品性能的实际变化较小,质量一致性更高,就要求减少材料中残余化学元素含量,因为这些残余元素共同作用的效果是难以预测的。因此必须严格控制纯钛铸锭的化学成分,以使铸锭成分结果保持一致性,同时保证了自ASTM钛金属规范性能指标首次发布后,性能指标逐步有了较大提高。

 

过去用来发展ASTM标准下钛材性能的40-50年的数据积累可能不在代表现代材料。生产过程中的改进使材料的化学成分更加一致,减少了残余化学成分含量(这些残余化学成分共同作用下的效果还没被完全掌控。)生产商不得不精确控制钛锭的化学成分,使铸锭成分和结果更加一致,同时,性能相比于ASTM标准下首次公布的钛金属性能参数,也有了很大的提高。

 

 

A 1998 review ofapproximately 250 Grade 2 titanium test reports found that all reportedultimate tensile strength, or UTS, values exceeded 60 ksi (410 MPa), well abovethe 50ksi (345 MPa) specification minimum. The results were presented to titaniumproducers with a proposal that if this were true in a substantially largersample, the industry might produce a competitive advantage for titanium bysimply changing the minimum specified UTS to reflect what was routinely beingachieved in practice.1,2 Sincethe American Society of Mechanical Engineers' Code Design Allowable Stressesfor titanium are controlled by the minimum UTS, a significant savings inequipment cost could be realized if higher allowable stresses based on a higherminimum specified UTS could be utilized. Because the ASME code is used as thebasis for a wide range of industrial equipment, the effect of such a changewould be significant.

1998版修订时,统计了约250Gr2纯钛实验报告,结果所有抗拉强度都大于410 Mpa,当然都比标准规定的最小指标345 Mpa高。提出的指标是建立在假定大量的试样是充分的和真实的基础上的。企业制造的产品若仅仅只是抗拉强度比通常标准规定的最小指标高,也会大大提高其竞争优势。由于美国机械工程协会设计时,纯钛的许用强度UTS按最小值计算,因此利用比标准规定的最小强度UTS高的材料在制造设备方面可达到极大节省。因为ASME标准被广泛使用于工业设备,这种变化意义将相当重大。

 

ROLE OF THEMATERIALS TECHNOLOGY INSTITUTE

材料技术协会的作用

The MaterialsTechnology Institute, headquartered in St. Louis,Mo., is an organization ofover 50 member companies, many of which use, fabricate, or manufacture titaniumor titanium equipment. MTI representatives include decision making personnelfrom many of the world's largest companies in the chemical and petrochemicalindustry. Each year MTI sponsors research projects that have a significant  benefit to  the  members' materials engineering efforts.    MTI member company representatives quicklysaw that an increase in the minimum specified tensile strength would lead toreductions in the cost of equipment they procure every year. In addition, MTI'smembership and reputation brought prestige to the project that was important ingetting cooperation from producers on a worldwide basis as well as gettingrecognition of the importance of the project by ASTM International, ASMEInternational, and other standards developing organizations.

材料技术协会,总部设在St. Louis,Mo.,是一个拥有50余人的企业机构,该部下属的多数企业是从事应用、制作或制造钛或钛设备。每年,由MTI的主办者研究与会员的材料工程具有重大利益的决策计划。MTI的代表包括决策者在内,均来自世界从事化学、化工行业的大型企业。MTI会员公司的决策者迅速感受到使用比标准规定强度最小值更高的钛设备将会大大降低他们每年生产设备的成本。另外,MTI之所以在国际ASTMASME和其他标准发展组织具有如此高的的全体成员威望,也正是由于他们的全体成员和制造商相互合作的重要设计方案带来了全世界的公认。

总部设立于密苏里州圣路易斯的材料技术协会,是一家拥有50多企业会员的组织,该组织下属的多数企业都是从事应用、加工,或是钛或钛设备的生产商。MTI(材料技术协会)的代表包括决策者本身在内,均来自化工领域享有国际盛名的大型企业的决策人员。每年材料技术协会发起的项目对于该组织企业会员来说都有着重大的意义。MTI(材料技术协会)的会员公司的决策者迅速发现使标准规定的抗拉强度最小值提高将大大降低每年购置设备的成本。此外,MTI(材料技术协会)的企业会员和声誉也给与之正在合作的来自世界各地合作商也带来了声望的同时,也得到来自美国ASTM国际、ASME国际和其他标准开发组织对该项目重要性的认可。

 

The largerstudy, begun in 2002 and jointly sponsored by the Materials TechnologyInstitute, the International Titanium Association, and MC Consulting,3included data from over 30 producers worldwide, and over 8,000 data points.These data showed that over 99.5 percent of the Grade 2 unalloyed titanium in adatabase of 5,280 tests had a UTS significantly higher than the minimum 50 ksi(345 MPa) in the existing specifications, while covering the full range ofyield strength, as shown in Figure 1. The study also showed that the unalloyedtitanium Grades 1, 3, and 4 wrought-mill products also have similarly higherUTS values than indicated by current ASTM and ASME specifications.

2002年,由材料技术协会、国际钛协会和MC咨询处共同负责开始深入研究,包括收集超过世界30家制造厂的8,000多组数据来源。5,280组统计数据表明:超过99.5%Gr.2纯钛的UTS(抗拉强度)明显高于现行标准最小指标50 ksi (345 MPa)。研究还表明,Gr.1Gr.3Gr.4纯钛的模锻产品的UTS(抗拉强度)值同样也比现行ASTMASME高。

 

   PROJECT OBJECTIVES

Grade 2titanium is widely used in the industrial corrosion sector and has become a defacto standard grade for most applications. This singular focus has allowed therelatively small titanium industry to offer a wide range of mill products andsizes, often from stock. Retaining thatfocus was a key objective of the project.

项目目标

Gr.2在工业上常用作抗腐蚀部件,是实际应用最广泛的一种纯钛。对小企业而言,从制坯开始,唯一的关注点在于制造的产品尺寸和加工量的控制。这一关注点对企业来说至关重要。

Gr.2在工业上常用作抗腐蚀部件,是实际应用最广泛的一种钛牌号。从库存角度而言,这一关注点使得规模较小的钛企业能提供更广泛的轧机产品和规格。保留这一重点是该项目的一个重要目标。

 

   Objectives are summarized as follows:

D Take advantage of higher minimum UTS in ASME Code and relatedconstruction.

D Maintain the standardization on Grade 2 for industrial and generalapplications.

D Maintain the availability of full range of titanium products resultingfrom effective standard  ization on Grade2 for most industrial and general applications.

D Minimize any tendency for producers to change the current ingotchemistry formulations (i.e., increasing the oxygen or iron content to be morecertain of making the higher tensile strength).

D Determine if changes in other unalloyed grades, i.e., Grades 1, 3 and 4were warranted.

对此计划概括介绍如下:

1、ASME标准中UTS指标最小值更高的意义和相关介绍

2、保持标准规定的工业级Gr.2的必要性和应用概况

3、要保证钛产品被广泛利用,需凭借标准的有效版本规定的适用于大多数工业及常规应用的Gr.2

4、是当前材料生产者减小铸锭化学成分目标值变化的要求(例如,增加FeO含量,势必会提高抗拉强度

5、确定是否调整其他纯钛牌号,如Gr.1Gr.3Gr.4的依据。

  PROPOSAL TO CHANGE MINIMUM UTS IN ASTM TITANIUM SPECIFICATIONS

    The project resulted in a proposal to ASTMCommittee to change the minimum UTS of not only Grade 2, but also of the other threeunalloyed titanium grades. This met with surprising resistance. However, theprocess to resolve the issues is a clear demonstration that the ASTM consensusprocess can produce a better result. Some of the concerns brought up bystakeholders are listed below.

调整ASTM标准中钛材UTS(抗拉强度)最小指标的计划

根据ASTM委员会BI0的提议方案,欲调整最小UTS的牌号不仅是Gr.2,还包括其他三种纯钛(Gr.1Gr.3Gr.4)。该提议肯定使人吃惊,并遭到反对。然而,解决这些问题是有确定程序的,该方案只有取得ASTM的大多数人同意才会通过。各代表一些讨论意见和关注点见下:

根据ASTM委员会BI0的提议,不仅要调整GR.2的最小UTS值,而且还包括其他三种纯钛(Gr.1Gr.3Gr.4)。该提议遇到了惊人的阻力。然而,解决这些问题的过程清楚的表明与ASTM提议一致将会有一个更好的结果。部分利益相关者的担忧见下:

 

There was concern thatadditional restrictions in the specification requirements would lead tounnecessary product rejections even though the control of chemistry required tomeet the    proposed strength appeared tobe easily within the normal capability of the ingot producers.

尽管生产厂在正常生产条件下,铸锭的化学成分控制很容易满足提出的强度要求,但规范的附录中还应涉及产品被拒收的可能性。

有人担忧,尽管生产厂在正常生产条件下,铸锭的化学成分控制很容易满足规定的强度要求,规格要求中的额外限制也会导致不必要的产品拒收。

 Some producers thought thatoverall consumption of titanium would decrease due to re  duced thickness requirements.

一些生产厂家则认为,由于范围变窄,钛的总消费量可能会减小。

There was a belief that achange in minimum UTS would cause the producers to reformulate their materialsto  meet the higher properties, giving upsome ductility and fabricability important to users of Grade 2 even though thedata showed that material above a specific oxygen level always met the 58 ksi(400 MPa) requirement and only material that had a low oxygen level (comparableto Grade 1) that was applied as Grade 2 fell below 58 ksi (400 MPa).

无庸置疑的是,由于UTS(抗拉强度)最小指标值调整,生产厂将会以改变原牌号各元素配比的目标值来满足更高的性能要求,这样会牺牲产品的延展性和对使用者来说至关重要Gr.2的成型性能。尽管已有数据表明,原材料的氧含量水平在规范的偏上限时,强度总会满足58 ksi (400 MPa)的要求,只有当Gr.2原材料的氧含量较低(与Gr.1比较)时,强度才达不到58 ksi (400 MPa)

ASTM Committee F04 on Medicaland Surgical Materials and Devices, which develops standards involving titaniumfor medical devices, known as the "F specifications,'' was concerned aboutany changes in basic specified properties because the regulatory process theyface to recognize such a change is long and costly. While the F specificationsspecify the affected properties independently, this was still a factor in notwanting to change the minimum

   property levels in the existing B (CommitteeBI0) grades. (The F specification grade requirements generally follow thegrades in the B specifications.)

ASTM医用和外科植入物材料和器械委员会 F04,开发包含医疗器械用钛材发展的标准就是众所周知的“(规范)”,该规范的最基本的性能指标调整之所以担心这个修订过程是漫长的,代价也是昂贵的。然而,F规范有自己规定的相互独立的性能,不愿调整现有B版纯钛级别中(委员会B10)性能最小值指标仅仅是其中的一种因素。(F规范的级别要求通常还是遵循B规范规定的级别。)

    The committee concluded that there was nocommercial incentive to increasing the UTS of Grade 1 since it is primarilyused for explosion cladding or plate heat exchanger applications where maximumductility is required and for chlorine anode substrates where higher electricalconductivity is also desirable. Committee B10 recognized that this need couldbe better served by reducing the minimum specified yield strength of Grade 1 toa level close to the lowest in the data base, which has the same effect on theratio of minimum UTS:YS of increasing the UTS of Grade 2. This was accompaniedby adding a supplemental requirement limiting the maximum yield strength to 40ksi (275MPa) instead of 45 ksi (310 MPa).The committee suggested reviewing thissituation in five years to see if a general shift in production would justifymaking the 40 ksi (275 MPa) upper limit mandatory.

委员会认为,提高Gr.1牌号的UTS是没有商业动机的,从起初只用于爆炸复合板或热交换管板开始,Gr.1就常用于对延展性要求高的场所,也常用作氯阳极层,这是由于它具有良好的电导率。委员会B10公认,将规范中Gr.1的屈服强度的指标下限降低到接近统计数据的最低值是最好的,这与提高Gr.2UTS对保持最小UTS:YS的比值不变是同样的作用。同时,增加了一附加要求,即用Gr.1最大屈服强度40ksi (275MPa)代替了原来的45ksi (310MPa)。委员会查阅回顾了近5年来产品总的变化,可以看出,强行将YS(屈服强度)上限改为40 ksi (275 MPa)是合理的。

The committeealso concluded that there was little interest in changing the minimum UTS of Grade3 because it is less widely used for pressure equipment than Grade 2, eventhough the data showed it could be done. Also,about 30 percent of the material(in the database) that could be dual certified as Grade 2 and 3 at existing Grade3 minimum tensile strength would not meet the proposed higher UTS.

委员会还认为,不调整Gr.3UTS最小值指标,因为虽然数据表明,它能应用于压力容器上,但它还是没有Gr.2牌号的应用广泛。同时,(数据库中)大约30%的材料既能被当作Gr.2,也能被用作Gr.3,可满足当前Gr.3的最小抗拉强度要求,但不能达到提议中提到的更高的Gr.3的指标。

 

    Finally, the committee concluded that there was no reason to changeGrade 4 because it is not listed in the ASME Code.

最后,委员会得出结论,决定不调Gr.4的指标,因为该牌号未列入ASME的牌号中。

    As a result, no changes were by the committee for Grade 3 or 4.

最终结果:委员会同意Gr.3Gr.4牌号的指标不作调整。

     THE H GRADES

H牌号

    To be responsive to the user interest represented by the MTI study, andto address the concerns expressed, ASTM Subcommittee B10.01 on Titaniumdeveloped a consensus to add the 58 ksi (400 MPa) material as a separate grade,butlinked it to the standard Grade 2 by assigning it a readily associated Grade 2Hdesignation.

  通过MTI研究对使用方最感兴趣的问题作出了答复,他们发表言论,ASTM委员会的附属委员会B10.01关于钛发展已形成了统一认识,他们希望增加一种新的、独立的强度为58ksi (400 MPa)的级别,将该级别命名为2HGr.2H),但很容易使人联想到Gr.2

         Grade 2H can always be dualcertified asGrade 2, and in nearly all cases, Grade 2 will meet the requirements of Grade2H. Since the standard numeric grades have been retained, it is expected thatingot producers will have minimal incentive to change their melt formulations.Retaining the standard numeric grades also addresses the medical applicationconcerns where the qualification of changes in material is costly. Thenomenclature "Grade 2H" is readily associated with "Grade 2,'minimizing the need to separately establish the H grades as a market standard.     These changes were incorporated in the2006a revision of the wrought titanium material specifications. H Gradecounterparts 7H, 16H, and 26H for the corrosion enhanced Grades 7 (Ti-0.12Pd),16 (Ti 0.06Pd), and 26 (Ti 0.1Ru) were also added to the specifications.

Gr.2H同时可被用做Gr.2,因为几乎在所有情况下,Gr.2也都能符合Gr.2H的要求。标准保持这样的级别,有利于刺激铸锭生产商不改变原有成分的目标值,保持这种级别的编号形式,也可避免由于医用成分与之有差异,使原料价格提高,从而限制钛材在医用的市场发展。“Gr.2H”这种命名法很容易使人联想到“Gr.2”,在标准中将“H 级别单独列为一个牌号至少是一种市场需要。在2006 a锻造钛材料规范的修订版中,已增加了这些变化。标准中增加的H级别的牌号还有7H, 16H26H,它们分别是以Gr.7(Ti-0.12Pd), Gr.16 (Ti 0.06Pd)Gr.26(Ti 0.1Ru)为基的用于提高耐蚀性的钛合金。

ESTIMATED IMPACT OF THE HIGHER STRENGTH LEVELS

高强度水平的影响评估

 

It is difficultto estimate exactly how much this change will save industrial users each year.The 16 percent increase to 58 ksi (400 MPa) from 50 ksi (345 MPa) minimum tensilestrength and the corresponding increase of design-allowable stress in ASME isexpected to reduce equipment cost by an average of 10-16 percent, assuminglabor and material have equivalent cost. The market for affected equipment was estimatedto be of the order of $100 million. Thus, if the 58 ksi (400MPa) grades werefully implemented into pressure equipment,the annual savings could be as high as$16 million, year after year.

每年究竟有多少使用者会改用新的级别(牌号)很难准确评估。最小抗拉强度从50 ksi (345 MPa)增加16%后为58 ksi (400MPa) ASME设计时的许用强度将相应增加,假使价格是由原材料和性能决定的,至少也将使设备的价格平均降低10~16%。钛设备在市场上的订购量总价约占10亿美元。因而,如果压力容器全部使用58 ksi (400MPa)级别的钛材,以后的每一年相当于可节约1.6亿美元。

  Finally, the higher strength addresses the currentshortage in titanium by reducing the amount of material required for a specificvessel. However, use of the H Grades is expected to result in more applicationswhere titanium is competitiveand over time a net increase in usage will result.//

无庸置疑,通过减少特种容器的的钛材的使用量,将会缓解目前钛材的紧缺局面。无论怎样,在哪里钛材有竞争,哪里H级别的钛材用量将增长,H级别用量不断增长也是必然趋势。

最后,目前可通过减少特钟容器所需的材料数量来解决当前高强度钛的短缺。然而,只要有竞争的地方,H级的使用预计就能被更广泛的应用,随着时间的推移它的净使用量也势必增加。

References

参考文献

1、McMaster, James A., "Is itTime to  Modernize the ASTMSpecifications for Unalloyed Titanium," presented at the "Titanium,Its Role, Its Growth and Its Applications in the  CPI" session, 49th CPI Exposition,  Javits Convention Center, New York,  New York, October 23~25, 2001

2McMaster, James A.,"Rationalization of Unalloyed Titanium Material Specifications to CurrentProduction Capabilities Offers Opportunities for  the Titanium Industry," presentedat  Corrosion 2003, San Diego, Califonia,March 16 to 20, 2003

3Final Project Report, Phase1,  ASTM Strength Revision Project  151-02, October 15, 2003, Materials  Technology Institute of the Chemicai ProcessIndustries, Inc., 1215  Fern RidgeParkway, Suite 116, St.

 Louis, Missouri 63141-4405

 

Benefits of new titanium specs

 

1、Opportunities exist for specification upgradesbased on modern material properties.

2、Producers as well as users canbenefit by tightening specifications to reflect improved productioncapabilities.

3、Change should be considered interms of both production risks and marketing benefits.

4、The H Grades will make titanium morecompetitive compared to other materials, and to some extent will help addressthe current shortage of titanium.

5、User groups can fulfill the role of developingor optimizing requirements for materials that has traditionally been filled bythe producer of the materials.

6、Revisiting existing old data with modernanalytical methods can produce useful/beneficial changes.

7、Tighter limits on properties in productspecifications may result in significantly higher design allowable stresses incodes and standards that use the statistical methods to determine theseallowable stresses.

8、Modernization of specifications to reflect theimprovements in product quality and consistency is one way ASTM committees cancontribute to making investments in improved material production worthwhile.

 

新规范的优点

1、以现有材料性能为基础,提高了本规范水平。

2、将高指标要求的产品纳入标准后,生产者和使用者都会受益。

3、标准的变化考虑了产品风险和市场效益。

4、与其他材料比较,H级别将使钛材更具有竞争力,更深一层说,会缓解目前的钛材短缺的局面。

5、有助于使用者实现发展或优化所需材料的作用,也有利于生产者按传统方式供应材料。

6、用现有的分析方法回顾积累的数据会发现这是一种有益的变化。

7、在产品规范中规定的性能极限值增高对按该级别(牌号)设计许用压力意义重大,因为设计者是按标准规定的极限用统计方法来决定许用压力的。

8、现代规范表现出的产品质量和质量一致性提高是ASTM委员会为提高材料生产质量所做投资的必然回报。