1. chemical composition examination
一般锻件不进行化学成分检查,化学成分是以冶炼时炉前取样分析为准。但是对重要的或可疑的锻件,可从锻件上切下一些切屑,采用化学分析或光谱分析方法检验化学成分。
General forgings do not carry out chemical composition inspection.
Chemical composition is based on sampling analysis before smelting. But
for important or suspicious forgings, some chips can be cut from the
forgings, and chemical composition can be checked by chemical analysis
or spectroscopic analysis.
2.尺寸和形状检查
2. size and shape check
(1)外观目测检查这是工序间检验常用的方法,凭肉眼观察锻件表面是否有折叠、裂纹、压伤、斑疤、表面过烧等缺陷。锻件表面隐蔽较深的缺陷,常在热处理并清理后进行观察。
(1) the visual inspection of the appearance is a common method of
inspection between the processes. By observing the defects of the
surface of the forgings, there are folds, cracks, bruising, scars, and
surface burning. Defects hidden on the surface of the forgings are often
observed after heat treatment and cleaning.
(2)尺寸测量检查包括:长、宽、高尺寸;平面的平行度、垂直度;轴线的弯曲度;内外圆的椭圆度;圆角半径;同心度;夹角和错移量等。锻件尺寸的检验是经常性的,测量用的工具分为通用性的和专用的。通用测量工具有卡尺、卡钳、游标卡尺等。生产量大时应该使用专用工具,如卡规、塞规、样板、专门夹具等。锻件要求进行精确尺寸检验时,除了可以用划线检查和专门样板外,可以采用由计算机进行控制和分析处理的检验仪器,或采用光学比较仪、光学投影仪作有关尺寸检查。
(2) size measurement includes: long, wide and high dimensions;
parallelism and perpendicularity of the plane; the curvature of the
axis; the ellipticity of the inner and outer circles; the radius of the
circle; the concentricity; the angle and the error displacement. The
inspection of forging size is regular. The tools used for measurement
are divided into general-purpose and special ones. The general measuring
tools are calipers, calipers, vernier calipers and so on. Special
tools, such as calipers, plug gauges, templates, special fixtures,
should be used when production is large. When the precision size test is
required for the forgings, the inspection instruments that are
controlled and analyzed by the computer, or the optical comparator and
the optical projector can be used to check the size.
(3)模具结构检查
为了保证模锻件的尺寸和形状,还应该检验模具结构。新锻模(或翻新后)的终锻模膛和预锻模膛,投入生产使用前,应该浇注铅样,或者浇注2份硝酸钠和1份硝酸钾组成的混合金属盐铸件,检查样件形状、飞边状态等,据此判断模膛设计是否合理。酸洗后的第一批锻件,要检查充满情况和是否存在折叠,以便确定锻模圆角、凸缘、筋部等设计的正确性。此外,也应该检查精密锻件的切边质量,以便确定切边模设计或安装上存在的质量问题。
(3) die structure inspection should also check the die structure in
order to ensure the size and shape of the die forging. Before the new
forging die (or refurbished) the final die bore and the pre forging die
bore, before the production is put into production, the lead sample
should be cast, or the mixed metal salt castings of 2 parts of sodium
nitrate and 1 parts of potassium nitrate are cast, and the shape of the
sample and the state of the flying are checked, and the design of the
mold chamber is judged reasonable. After the pickling, the first batch
of forgings should be checked for filling and folding, so as to
ascertain the correctness of the design of forging die rounded, flange,
rib and so on. In addition, the trimming quality of precision forgings
should be checked in order to determine the quality problems existing in
the design and installation of trimming dies.
3.力学性能检验
3. mechanical properties test
根据锻件的重要性及材料特性来确定检验项目。力学性能试样必须从同一熔炼炉,同一热处理炉中取出的锻件上切取。试样切取、试样形状尺寸、检验方法均按国家标准规定进行。
The inspection items are determined according to the importance and
material properties of the forgings. The mechanical properties of the
specimens must be cut from the forgings taken from the same smelting
furnace and the same heat treatment furnace. Sample cutting, sample size
and testing methods are carried out in accordance with national
standards.
(1)硬度试验硬度试验是生产中常用的、判断锻件力学性能最简便的方法。硬度试验的目的是:保证锻件机械加工时有正常的切削性能;判断锻件表面的脱碳情况;了解锻件内部组织的不均匀程度。硬度试验一般在锻件热处理后进行,可使用布氏硬度或洛氏硬度计等。
(1) hardness test is the easiest way to judge the mechanical
properties of forgings in production. The purpose of the hardness test
is to ensure the normal cutting performance of the forging parts, to
judge the decarbonization of the forgings, and to understand the
inhomogeneous degree of the internal structure of the forgings. Hardness
test is usually carried out after forging heat treatment. Brinell
hardness or Rockwell hardness tester can be used.
(2)拉伸试验测定在单向静拉力下的屈服极限仃。、强度极限crb、延伸率艿及截面收缩率等。
(2) tensile test is used to determine yield limit under uniaxial
tension. The ultimate strength is CRB, elongation and shrinkage.
(3)冲击试验用来检验材料或锻件的韧性。工作时受冲击载荷与振动载荷,或在高温、高速下工作的零件,如涡轮盘、涡轮叶片等,一般需要进行冲击试验。
(3) impact test is used to check the toughness of materials or
forgings. Shock tests are usually required for working parts, such as
shock loads and vibration loads, or parts operating at high temperatures
and high speeds, such as turbine discs and turbine blades.