JB-T 8421-1996 钢质自由锻件检验通用规则

J32JB/T8421－1996钢质自由锻件检验通用规则1996-09-03发布1997-07-01实施中华人民共和国机械工业部发布前言1范围····················································································································································································································12引用标准·········································································································································································································13化学成分·········································································································································································································14力学性能·········································································································································································································35其他检验项目·······························································································································································································86外观质量·········································································································································································································87形状和尺寸····································································································································································································98标志····················································································································································································································99质量证明书····································································································································································································9附录A（标准的附录）加权平均分析法·········································································································································10JB/T8421－1996目次I前言钢质自由锻件(以下简称锻件)的质量检验，是控制锻件质量的重要手段。由于锻件的服役条件、材料及热处理状态、形状、尺寸、重量、组批条件的不同，控制锻件质量的检验项目就有所差异。本标准是专用于一般工业用碳素钢和合金钢自由锻件的通用检验标准，根据锻件的分级，确定检验项目。检验项目有化学成分、力学性能、高低倍组织、超声波探伤、外观质量等，还明确规定了力学性能试验的试样数量、取样位置和试样方向、复试和重新热处理等内容，从而为一般锻件的检验提供了统一的依据。本标准中，锻件成品化学成分分析值的允许偏差表等同采用ASTMA788《一般要求锻钢件标准》的内容，试样数量、取样位置和试样方向等内容参照采用JISG0306《锻钢件检验通则》和ASTMA668《一般工业用碳素钢和合金钢锻件标准》的内容，本标准附录A等效采用ASTMA788的附录A。本标准从1997年7月1日起实施。本标准的附录A是标准的附录。本标准由全国锻压标准化技术委员会提出并归口。本标准负责起草单位：中国第二重型机械集团公司。本标准参加起草单位：机械工业部北京机电研究所。本标准主要起草人：王立、彭芸、胡加尔、蔡福林。JB/T8421－199611范围本标准规定了钢质自由锻件(以下简称锻件)检验的通用规则。本标准适用于一般工业用碳素钢和合金钢锻件，不适用于专门用途或有特殊要求的锻件。2引用标准下列标准所包含的条文，通过在本标准中引用而构成为本标准的条文。本标准出版时，所示版本均为有效。所有标准都会被修订，使用本标准的各方应探讨使用下列标准昀新版本的可能性。GB222—84钢的化学分析用试样取样法及成品化学成分允许偏差GB223.1～223.75—81～91钢铁及合金化学分析方法GB226—91钢的低倍组织及缺陷酸浸检验法GB228—87金属拉伸试验法GB229—84金属夏比(U型缺口)冲击试验方法GB/T230—91金属洛氏硬度试验方法GB231—84金属布氏硬度试验方法GB1814—79钢材断口检验法GB1979—80结构钢低倍组织缺陷评级图GB2106—80金属夏比(V型缺口)冲击试验方法GB2971—80碳素钢和低合金钢断口检验方法GB4236—84钢的硫印检验方法GB4341—84金属肖氏硬度试验方法GB6394—86金属平均晶粒度测定方法GB8170—87数值修约规则GB10561—89钢中非金属夹杂物显微评定方法GB/T12363—90锻件功能分类GB/T13298—91金属显微组织检验方法GB/T13299—91钢的显微组织评定方法GB/T15826—1995锤上钢质自由锻件机械加工余量与公差JB4009—85接触式超声纵波直射探伤方法ZBJ04005—87渗透探伤方法ZBJ04006—87钢铁材料的磁粉探伤方法ZBJ32003—88水压机上自由锻件机械加工余量与公差3化学成分3.1熔炼分析3.1.1钢厂应对每炉钢水浇注时取熔炼分析试样，测定材料标准中所规定元素的百分含量。分析结果应符合该材料标准的要求。机械工业部1996-09-03批准中华人民共和国机械行业标准钢质自由锻件检验通用规则JB/T8421－19961997-07-01实施JB/T8421－199623.1.2若是多炉钢水注入大钢包，则应对该钢包钢水进行化学分析，测定的化学成分应符合该材料标准的要求。3.1.3对于多炉合浇钢锭，可取每炉分析值或加权平均值，其结果应符合该材料标准的要求。3.1.4对于电渣重熔钢锭，若是同一炉号电极的重熔钢锭，则该重熔钢锭(或锻件)的化学分析应作为熔炼分析；若由不同炉号电极依次重熔，则应对每一炉号至少一根电极在重熔钢锭中对应的每个区段进行化学分析，每个区段的测定结果均应符合该材料标准的要求，该重熔钢锭的熔炼分析结果，应由各区段各自化学分析的加权平均值来表示。3.1.5若熔炼分析试样不符合要求，则钢厂可从钢锭或锻件表面附近的合适位置取代替试样。3.1.6凡外购钢锭、钢坯或轧材，其质量证明书中应有钢厂的熔炼分析结果。制造厂可进行入厂复验。3.2成品分析3.2.1需方可在代表每炉钢水的锻件上或多炉合浇的锻件上取样分析。取样规定如下：a)实心锻件及盘类锻件取自原尺寸加长段端面距外表面三分之一半径(或六分之一对角线)范围内的任一处；b)空心锻件取自原尺寸加长段端面二分之一壁厚处；c)所有锻件也可在力学性能试验的试样上取成品分析试样。3.2.2成品分析测定的化学成分，应符合锻件材料标准规定的要求，但允许有表1规定的偏差。表1成品分析化学成分的允许偏差量超过规定的上限或低于规定的下限的允许偏差量%横截面积cm2元素成分范围≤650＞650～1300＞1300～2600＞2600～5200＞5200～10300＞10300碳≤0.050.0050.0050.0050.010.010.010.06～0.100.010.010.010.010.010.010.11～0.250.020.030.030.040.050.050.26～0.550.030.040.040.050.060.06≥0.560.040.050.050.060.070.07锰≤0.900.030.040.050.060.070.08≥0.910.060.060.070.080.080.09磷≤0.050.0080.0080.0100.0100.0150.015硫≤0.0300.0050.0050.0050.0050.0060.0060.031～0.0600.0080.0100.0100.0100.0150.015硅≤0.350.020.030.040.040.050.06≥0.360.050.060.060.070.070.08镍≤1.000.030.030.030.030.030.031.01～2.000.050.050.050.050.050.052.01～5.300.070.070.070.070.070.075.31～10.000.100.100.100.100.100.10≥10.010.150.150.150.150.150.15铬≤0.900.030.040.040.050.050.060.91～2.100.050.060.060.070.070.082.11～10.000.100.100.120.140.150.1610.01～15.000.150.150.150.170.170.1915.01～20.000.200.200.200.220.240.24≥20.010.250.250.250.270.270.29JB/T8421－19963表1（完）超过规定的上限或低于规定的下限的允许偏差量%横截面积cm2元素成分范围≤650＞650～1300＞1300～2600＞2600～5200＞5200～10300＞10300钼≤0.200.010.020.020.020.030.030.21～0.400.020.030.030.030.040.040.41～1.150.03